% University of Cambridge Computer Laboratory Technical Reports
% Automatically generated file. Last updated: 2012-02-09

@TechReport{UCAM-CL-TR-1,
  author =	 {Challis, M.F.},
  title = 	 {{The JACKDAW database package}},
  year = 	 1974,
  month = 	 oct,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-1.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This report describes a general database package which
            	  has been implemented in BCPL on an IBM 370/165 at the
            	  University of Cambridge. One current application is the
            	  provision of an administrative database for the Computing
            	  Service.
            	  
            	  Entries within a database may include (in addition to
            	  primitive fields such as `salary' and `address') links to
            	  other entries: each link represents a relationship
            	  between two entries and is always two-way.
            	  
            	  Generality is achieved by including within each database
            	  class definitions which define the structure of the
            	  entries within it; these definitions may be interrogated
            	  by program.
            	  
            	  The major part of the package presents a procedural
            	  interface between an application program and an existing
            	  database, enabling entries and their fields to be
            	  created, interrogated, updated and deleted. The creation
            	  of a new database (or modification of an existing one) by
            	  specifying the class definitions is handled by a separate
            	  program.
            	  
            	  The first part of the report describes the database
            	  structure and this is followed by an illustration of the
            	  procedural interface. Finally, some of the implementation
            	  techniques used to insure integrity of the database are
            	  described.},
  number = 	 {UCAM-CL-TR-1}
}

@TechReport{UCAM-CL-TR-2,
  author =	 {Larmouth, J.},
  title = 	 {{Scheduling for a share of the machine}},
  year = 	 1974,
  month = 	 oct,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-2.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This paper describes the mechanism used to schedule jobs
            	  and control machine use on the IBM 370/165 at Cambridge
            	  University, England. The same algorithm is currently
            	  being used in part at the University of Bradford and
            	  implementations are in progress or under study for a
            	  number of other British Universities.
            	  
            	  The system provides computer management with a simple
            	  tool for controlling machine use. The managerial decision
            	  allocates a share of the total machine resources to each
            	  user of the system, either directly, or via a hierarchial
            	  allocation scheme. The system then undertakes to vary the
            	  turnaround of user jobs to ensure that those decisions
            	  are effective, no matter what sort of work the user is
            	  doing.
            	  
            	  At the user end of the system we have great flexibility
            	  in the way in which he uses the resources he has
            	  received, allowing him to get a rapid turnaround for
            	  those (large or small) jobs which require it, and a
            	  slower turnaround for other jobs. Provided he does not
            	  work at a rate exceeding that appropriate to his share of
            	  the machine, he can request, for every job he submits,
            	  the `deadline' by which he wants it running, and the
            	  system will usually succeed in running his job at about
            	  the requested time -- rarely later, and only occasionally
            	  sooner.
            	  
            	  Every job in the machine has its own `deadline', and the
            	  machine is not underloaded. Within limits, each user can
            	  request his jobs back when he wants them, and the system
            	  keeps his use to within the share of the machine he has
            	  been given. The approach is believed to be an original
            	  one and to have a number of advantages over more
            	  conventional scheduling and controlling algorithms.},
  number = 	 {UCAM-CL-TR-2}
}

@TechReport{UCAM-CL-TR-3,
  author =	 {Stoneley, A.J.M.},
  title = 	 {{A replacement for the OS/360 disc space management
         	   routines}},
  year = 	 1975,
  month = 	 apr,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-3.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {In the interest of efficiency, the IBM disc space
            	  management routines (Dadsm) have been completely replaced
            	  in the Cambridge 370/165.
            	  
            	  A large reduction in the disc traffic has been achieved
            	  by keeping the lists of free tracks in a more compact
            	  form and by keeping lists of free VTOC blocks. The real
            	  time taken in a typical transaction has been reduced by a
            	  factor of twenty.
            	  
            	  By writing the code in a more appropriate form than the
            	  original, the size has been decreased by a factor of
            	  five, thus making it more reasonable to keep it
            	  permanently resident. The cpu requirement has decreased
            	  from 5\% to 0.5\% of the total time during normal
            	  service.
            	  
            	  The new system is very much safer than the old in the
            	  fact of total system crashes. The old system gave little
            	  attention to the consequences of being stopped in
            	  mid-flight, and it was common to discover an area of disc
            	  allocated to two files. This no longer happens.},
  number = 	 {UCAM-CL-TR-3}
}

@TechReport{UCAM-CL-TR-4,
  author =	 {Stoneley, A.J.M.},
  title = 	 {{The dynamic creation of I/O paths under OS/360-MVT}},
  year = 	 1975,
  month = 	 apr,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-4.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {In a large computer it is often desirable and convenient
            	  for an ordinary program to be able to establish for
            	  itself a logical connection to a peripheral device. This
            	  ability is normally provided through a routine within the
            	  operating system which may be called by any user program
            	  at any time. OS/360 lacks such a routine. For the batch
            	  job, peripheral connections can only be made through the
            	  job control language and this cannot be done dynamically
            	  at run-time. In the restricted context of TSO (IBM's
            	  terminal system) a routine for establishing peripheral
            	  connections does exist, but it is extremely inefficient
            	  and difficult to use.
            	  
            	  This paper describes how a suitable routine was written
            	  and grafted into the operating system of the Cambridge
            	  370/165.},
  number = 	 {UCAM-CL-TR-4}
}

@TechReport{UCAM-CL-TR-5,
  author =	 {Hazel, P. and Stoneley, A.J.M.},
  title = 	 {{Parrot -- A replacement for TCAM}},
  year = 	 1976,
  month = 	 apr,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-5.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The terminal driving software and hardware for the
            	  Cambridge TSO (Phoenix) system is described. TCAM and the
            	  IBM communications controller were replaced by a locally
            	  written software system and a PDP-11 complex. This
            	  provided greater flexibility, reliability, efficiency and
            	  a better ``end-user'' interface than was possible under a
            	  standard IBM system.},
  number = 	 {UCAM-CL-TR-5}
}

@TechReport{UCAM-CL-TR-6,
  author =	 {Birrell, Andrew D.},
  title = 	 {{System programming in a high level language}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-6}
}

@TechReport{UCAM-CL-TR-7,
  author =	 {Hopper, Andrew},
  title = 	 {{Local area computer communications network}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-7}
}

@TechReport{UCAM-CL-TR-9,
  author =	 {Cook, Douglas John},
  title = 	 {{Evaluation of a protection system}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-9}
}

@TechReport{UCAM-CL-TR-10,
  author =	 {Pezarro, Mark Theodore},
  title = 	 {{Prediction oriented description of database systems}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-10}
}

@TechReport{UCAM-CL-TR-11,
  author =	 {Boguraev, Branimir Konstatinov},
  title = 	 {{Automatic resolution of linguistic ambiguities}},
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-11.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The thesis describes the design, implementation and
            	  testing of a natural language analysis system capable of
            	  performing the task of generating paraphrases in a highly
            	  ambiguous environment. The emphasis is on incorporating
            	  strong semantic judgement in an augmented transition
            	  network grammar: the system provides a framework for
            	  examining the relationship between syntax and semantics
            	  in the process of text analysis, especially while
            	  treating the related phenomena of lexical and structural
            	  ambiguity. Word-sense selection is based on global
            	  analysis of context within a semantically well-formed
            	  unit, with primary emphasis on the verb choice. In
            	  building structures representing text meaning, the
            	  analyser relies not on screening through many alternative
            	  structures -- intermediate, syntactic or partial semantic
            	  -- but on dynamically constructing only the valid ones.
            	  The two tasks of sense selection and structure building
            	  are procedurally linked by the application of semantic
            	  routines derived from Y. Wilks' preference semantics,
            	  which are invoked at certain well chosen points of the
            	  syntactic constituent analysis -- this delimits the scope
            	  of their action and provides context for a particular
            	  disambiguation technique. The hierarchical process of
            	  sentence analysis is reflected in the hierarchical
            	  organisation of application of these semantic routines --
            	  this allows the efficient coordination of various
            	  disambiguation techniques, and the reduction of syntactic
            	  backtracking, non-determinism in the grammar, and
            	  semantic parallelism. The final result of the analysis
            	  process is a dependency structure providing a meaning
            	  representation of the input text with labelled components
            	  centred on the main verb element, each characterised in
            	  terms of semantic primitives and expressing both the
            	  meaning of a constituent and its function in the overall
            	  textual unit. The representation serves as an input to
            	  the generator, organised around the same underlying
            	  principle as the analyser -- the verb is central to the
            	  clause. Currently the generator works in paraphrase mode,
            	  but is specifically designed so that with minimum effort
            	  and virtually no change in the program control structure
            	  and code it could be switched over to perform
            	  translation.
            	  
            	  The thesis discusses the rationale for the approach
            	  adopted, comparing it with others, describes the system
            	  and its machine implementation, and presents experimental
            	  results.},
  number = 	 {UCAM-CL-TR-11}
}

@TechReport{UCAM-CL-TR-12,
  author =	 {Oakley, M.R.A. and Hazel, P.},
  title = 	 {{HASP ``IBM 1130'' multileaving remote job entry protocol
         	   with extensions as used on the University of Cambridge IBM
         	   370/165}},
  year = 	 1979,
  month = 	 sep,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-12}
}

@TechReport{UCAM-CL-TR-13,
  author =	 {Hazel, Philip},
  title = 	 {{Resource allocation and job scheduling}},
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-13.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The mechanisms for sharing the resources of the
            	  Cambridge IBM 370/165 computer system among many
            	  individual users are described. File store is treated
            	  separately from other resources such as central processor
            	  and channel time. In both cases, flexible systems that
            	  provide incentives to thrifty behaviour are used. The
            	  method of allocating resources directly to users rather
            	  than in a hierarchical manner via faculties and
            	  departments is described, and its social acceptability is
            	  discussed.},
  number = 	 {UCAM-CL-TR-13}
}

@TechReport{UCAM-CL-TR-14,
  author =	 {Powers, J.S.},
  title = 	 {{Store to store swapping for TSO under OS/MVT}},
  year = 	 1980,
  month = 	 jun,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-14.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {A system of store-to-store swapping incorporated into
            	  TSO on the Cambridge IBM 370/165 is described. Unoccupied
            	  store in the dynamic area is used as the first stage of a
            	  two-stage backing store for swapping time-sharing
            	  sessions; a fixed-head disc provides the second stage.
            	  The performance and costs of the system are evaluated.},
  number = 	 {UCAM-CL-TR-14}
}

@TechReport{UCAM-CL-TR-15,
  author =	 {Wilson, I.D.},
  title = 	 {{The implementation of BCPL on a Z80 based microcomputer}},
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-15.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The main aim of this project was to achieve as full an
            	  implementation as possible of BCPL on a floppy disc based
            	  microcomputer, running CP/M or CDOS (the two being
            	  esentially compatible). On the face of it there seemed so
            	  many limiting factors, that, when the project was
            	  started, it was not at all clear which one (if any) would
            	  become a final stumbling block. As it happened, the major
            	  problems that cropped up could be programmed round, or
            	  altered in such a way as to make them soluble.
            	  
            	  The main body of the work splits comfortably into three
            	  sections, and the writer hopes that, in covering each
            	  section separately, to be able to show how the whole
            	  project fits together into the finished implementation.},
  number = 	 {UCAM-CL-TR-15}
}

@TechReport{UCAM-CL-TR-16,
  author =	 {Dion, Jeremy},
  title = 	 {{Reliable storage in a local network}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-16}
}

@TechReport{UCAM-CL-TR-17,
  author =	 {Boguraev, B.K. and Sp{\"a}rck Jones, K. and Tait, J.I.},
  title = 	 {{Three papers on parsing}},
  year = 	 1982,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-17}
}

@TechReport{UCAM-CL-TR-18,
  author =	 {W{\"o}rdenweber, Burkard},
  title = 	 {{Automatic mesh generation of 2 \& 3 dimensional
         	   curvilinear manifolds}},
  year = 	 1981,
  month = 	 nov,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-18}
}

@TechReport{UCAM-CL-TR-19,
  author =	 {Cater, Arthur William Sebright},
  title = 	 {{Analysis and inference for English}},
  year = 	 1981,
  month = 	 sep,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-19}
}

@TechReport{UCAM-CL-TR-20,
  author =	 {Cohn, Avra and Milner, Robin},
  title = 	 {{On using Edinburgh LCF to prove the correctness of a
         	   parsing algorithm}},
  year = 	 1982,
  month = 	 feb,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-20.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The methodology of Edinburgh LCF, a mechanized
            	  interactive proof system is illustrated through a problem
            	  suggested by Gloess -- the proof of a simple parsing
            	  algorithm. The paper is self-contained, giving only the
            	  relevant details of the LCF proof system. It is shown how
            	  tactics may be composed in LCF to yield a strategy which
            	  is appropriate for the parser problem but which is also
            	  of a generally useful form. Also illustrated is a general
            	  mechanized method of deriving structural induction rules
            	  within the system.},
  number = 	 {UCAM-CL-TR-20}
}

@TechReport{UCAM-CL-TR-21,
  author =	 {Cohn, A.},
  title = 	 {{The correctness of a precedence parsing algorithm in LCF}},
  year = 	 1982,
  month = 	 apr,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-21.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This paper describes the proof in the LCF system of a
            	  correctness property of a precedence parsing algorithm.
            	  The work is an extension of a simpler parser and proof by
            	  Cohn and Milner (Cohn \& Milner 1982). Relevant aspects
            	  of the LCF system are presented as needed. In this paper,
            	  we emphasize (i) that although the current proof is much
            	  more complex than the earlier one, mqany of the same
            	  metalanguage strategies and aids developed for the first
            	  proof are used in this proof, and (ii) that (in both
            	  cases) a general strategy for doing some limited forward
            	  search is incorporated neatly into the overall
            	  goal-oriented proof framework.},
  number = 	 {UCAM-CL-TR-21}
}

@TechReport{UCAM-CL-TR-22,
  author =	 {Robson, M.},
  title = 	 {{Constraints in CODD}},
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-22.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The paper describes the implementation of the data
            	  structuring concepts of domains, intra-tuple constraints
            	  and referential constraints in the relational DBMS CODD.
            	  All of these constraints capture some of the semantics of
            	  the database's application.
            	  
            	  Each class of constraint is described briefly and it is
            	  shown how each of them is specified. The constraints are
            	  stored in the database giving a centralised data model,
            	  which contains descriptions of procedures as well as of
            	  statistic structures. Some extensions to the notion of
            	  referential constraint are proposed and it is shown how
            	  generalisation hierarchies can be expressed as sets of
            	  referential constraints. It is shown how the stored data
            	  model is used in enforcement of the constraints.},
  number = 	 {UCAM-CL-TR-22}
}

@TechReport{UCAM-CL-TR-23,
  author =	 {Tait, J.I.},
  title = 	 {{Two papers about the scrabble summarising system}},
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-23.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This report contains two papers which describe parts of
            	  the Scrabble English summarizing system. The first,
            	  ``Topic identification techniques for predictive language
            	  analyzers'' has been accepted as a short communication
            	  for the 9th International COnference on Computational
            	  Linguistics, in Prague. The second, ``General summaries
            	  using a predictive language analyser'' is an extended
            	  version of a discussion paper which will be presented at
            	  the European Conference on Artificial Intelligence in
            	  Paris. Both conferences will take place during July 1982.
            	  
            	  The [second] paper describes a computer system capable of
            	  producing coherent summaries of English texts even when
            	  they contain sections which the system has not understood
            	  completely. The system employs an analysis phase which is
            	  not dissimilar to a script applier together with a rather
            	  more sophisticated summariser than previous systems. Some
            	  deficiencies of earlier systems are pointed out, and ways
            	  in which the current implementation overcomes them are
            	  discussed.},
  number = 	 {UCAM-CL-TR-23}
}

@TechReport{UCAM-CL-TR-24,
  author =	 {Boguraev, B.K. and Sp{\"a}rck Jones, K.},
  title = 	 {{Steps towards natural language to data language
         	   translation using general semantic information}},
  year = 	 1982,
  month = 	 mar,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-24}
}

@TechReport{UCAM-CL-TR-25,
  author =	 {Alshawi, Hiyan},
  title = 	 {{A clustering technique for semantic network processing}},
  year = 	 1982,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-25}
}

@TechReport{UCAM-CL-TR-26,
  author =	 {Knight, Brian James},
  title = 	 {{Portable system software for personal computers on a
         	   network}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-26}
}

@TechReport{UCAM-CL-TR-27,
  author =	 {Johnson, Martyn Alan},
  title = 	 {{Exception handling in domain based systems}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-27}
}

@TechReport{UCAM-CL-TR-28,
  author =	 {Matthews, D.C.J.},
  title = 	 {{Poly report}},
  year = 	 1982,
  month = 	 aug,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-28.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Poly was designed to provide a programming system with
            	  the same flexibility as a dynamically typed language but
            	  without the run-time oveheads. The type system, based on
            	  that of Russel allows polymorpphic operations to be used
            	  to manipulate abstract objects, but with all the type
            	  checking being done at compile-time. Types may be passed
            	  explicitly or by inference as parameters to procedures,
            	  and may be returned from procedures. Overloading of names
            	  and generic types can be simulated by using the general
            	  procedure mechanism. Despite the generality of the
            	  language, or perhaps because of it, the type system is
            	  very simple, consisting of only three classes of object.
            	  There is an exception mechanism, similar to that of CLU,
            	  and the exceptions raised in a procedure are considered
            	  as part of its `type'. The construction of abstract
            	  objects and hiding of internal details of the
            	  representation come naturally out of the type system.},
  number = 	 {UCAM-CL-TR-28}
}

@TechReport{UCAM-CL-TR-29,
  author =	 {Matthews, D.C.J.},
  title = 	 {{Introduction to Poly}},
  year = 	 1982,
  month = 	 may,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-29.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This report is a tutorial introduction to the
            	  programming language Poly. It describes how to write and
            	  run programs in Poly using the VAX/UNIX implementation.
            	  Examples given include polymorphic list functions, a
            	  double precision integer package and a subrange type
            	  constructor.},
  number = 	 {UCAM-CL-TR-29}
}

@TechReport{UCAM-CL-TR-30,
  author =	 {Wilkes, John},
  title = 	 {{A portable BCPL library}},
  year = 	 1982,
  month = 	 oct,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-30}
}

@TechReport{UCAM-CL-TR-31,
  author =	 {Fairbairn, J.},
  title = 	 {{Ponder and its type system}},
  year = 	 1982,
  month = 	 nov,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-31.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This note describes the programming language ``Ponder'',
            	  which is designed according to the principles of
            	  referencial transparency and ``orthogonality'' as in
            	  [vWijngaarden 75]. Ponder is designed to be simple, being
            	  functional with normal order semantics. It is intended
            	  for writing large programmes, and to be easily tailored
            	  to a particular application. It has a simple but powerful
            	  polymorphic type system.
            	  
            	  The main objective of this note is to describe the type
            	  system of Ponder. As with the whole of the language
            	  design, the smallest possible number of primitives is
            	  built in to the type system. Hence for example, unions
            	  and pairs are not built in, but can be constructed from
            	  other primitives.},
  number = 	 {UCAM-CL-TR-31}
}

@TechReport{UCAM-CL-TR-32,
  author =	 {Boguraev, B.K. and Sp{\"a}rck Jones, K.},
  title = 	 {{How to drive a database front end using general semantic
         	   information}},
  year = 	 1982,
  month = 	 nov,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-32}
}

@TechReport{UCAM-CL-TR-33,
  author =	 {Carroll, John A.},
  title = 	 {{An island parsing interpreter for Augmented Transition
         	   Networks}},
  year = 	 1982,
  month = 	 oct,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-33.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This paper describes the implementation of an `island
            	  parsing' interpreter for an Augmented Transition Network
            	  (ATN). The interpreter provides more complete coverage of
            	  Woods' original ATM formalism than his later island
            	  parsing implementation; it is written in LISP and has
            	  been modestly tested.},
  number = 	 {UCAM-CL-TR-33}
}

@TechReport{UCAM-CL-TR-34,
  author =	 {Paulson, Larry},
  title = 	 {{Recent developments in LCF: examples of structural
         	   induction}},
  year = 	 1983,
  month = 	 jan,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-34}
}

@TechReport{UCAM-CL-TR-35,
  author =	 {Paulson, Larry},
  title = 	 {{Rewriting in Cambridge LCF}},
  year = 	 1983,
  month = 	 feb,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-35.dvi.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Many automatic theorem-provers rely on rewriting. Using
            	  theorems as rewrite rules helps to simplify the subgoals
            	  that arise during a proof.
            	  
            	  LCF is an interactive theorem-prover intended for
            	  reasoning about computation. Its implementation of
            	  rewriting is presented in detail. LCF provides a family
            	  of rewriting functions, and operators to combine them. A
            	  succession of functions is described, from pattern
            	  matching primitives to the rewriting tool that performs
            	  most inferences in LCF proofs.
            	  
            	  The design is highly modular. Each function performs a
            	  basic, specific task, such as recognizing a certain form
            	  of tautology. Each operator implements one method of
            	  building a rewriting function from simpler ones. These
            	  pieces can be put together in numerous ways, yielding a
            	  variety of rewriting strategies.
            	  
            	  The approach involves programming with higher-order
            	  functions. Rewriting functions are data values, produced
            	  by computation on other rewriting functions. The code is
            	  in daily use at Cambridge, demonstrating the practical
            	  use of functional programming.},
  number = 	 {UCAM-CL-TR-35}
}

@TechReport{UCAM-CL-TR-36,
  author =	 {Paulson, Lawrence},
  title = 	 {{The revised logic PPLAMBDA : A reference manual}},
  year = 	 1983,
  month = 	 mar,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-36.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {PPLAMBDA is the logic used in the Cambridge LCF proof
            	  assistant. It allows Natural Deduction proofs about
            	  computation, in Scott's theory of partial orderings. The
            	  logic's syntax, axioms, primitive inference rules,
            	  derived inference rules and standard lemmas are described
            	  as are the LCF functions for building and taking apart
            	  PPLAMBDA formulas.
            	  
            	  PPLAMBDA's rule of fixed-point induction admits a wide
            	  class of inductions, particularly where flat or finite
            	  types are involved. The user can express and prove these
            	  type properties in PPLAMBDA. The induction rule accepts a
            	  list of theorems, stating type properties to consider
            	  when deciding to admit an induction.},
  number = 	 {UCAM-CL-TR-36}
}

@TechReport{UCAM-CL-TR-37,
  author =	 {Girling, Christopher Gray},
  title = 	 {{Representation and authentication on computer networks}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-37}
}

@TechReport{UCAM-CL-TR-38,
  author =	 {Gray, Mike},
  title = 	 {{Views and imprecise information in databases}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-38}
}

@TechReport{UCAM-CL-TR-39,
  author =	 {Paulson, Lawrence},
  title = 	 {{Tactics and tacticals in Cambridge LCF}},
  year = 	 1983,
  month = 	 jul,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-39}
}

@TechReport{UCAM-CL-TR-40,
  author =	 {Stoye, W.},
  title = 	 {{The SKIM microprogrammer's guide}},
  year = 	 1983,
  month = 	 oct,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-40}
}

@TechReport{UCAM-CL-TR-41,
  author =	 {Gordon, Mike},
  title = 	 {{LCF\_LSM, A system for specifying and verifying hardware}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-41}
}

@TechReport{UCAM-CL-TR-42,
  author =	 {Gordon, Mike},
  title = 	 {{Proving a computer correct with the LCF\_LSM hardware
         	   verification system}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-42}
}

@TechReport{UCAM-CL-TR-43,
  author =	 {Leslie, Ian Malcom},
  title = 	 {{Extending the local area network}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  abstract = 	 {This dissertation is concerned with the development of a
            	  large computer network which has many properties
            	  associated with local area computer networks, including
            	  high bandwidth and lower error rates. The network is made
            	  up of component local area networks, specifically
            	  Cambridge rings, which are connected either through local
            	  ring-ring bridges or through a high capacity satellite
            	  link. In order to take advantage of the characteristics
            	  of the resulting network, the protocols used are the same
            	  simple protocols as those used on a single Cambridge
            	  ring. This in turn allows many applications, which might
            	  have been thought of as local area network applications,
            	  to run on the larger network.
            	  
            	  Much of this work is concerned with an interconnection
            	  strategy which allows hosts of different component
            	  networks to communicate in a flexible manner without
            	  building an extra internetwork layer into protocol
            	  hierarchy. The strategy arrived at is neither a datagram
            	  approach nor a system of concatenated error and flow
            	  controlled virtual circuits. Rather, it is a lightweight
            	  virtual circuit approach which preserves the order of
            	  blocks sent on a circuit, but which makes no other
            	  guarantees about the delivery of these blocks. An extra
            	  internetwork protocol layer is avoided by modifying the
            	  system used on a single Cambridge ring which binds
            	  service names to addresses so that it now binds service
            	  names to routes across the network.},
  number = 	 {UCAM-CL-TR-43}
}

@TechReport{UCAM-CL-TR-44,
  author =	 {Paulson, Lawrence},
  title = 	 {{Structural induction in LCF}},
  year = 	 1983,
  month = 	 nov,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-44}
}

@TechReport{UCAM-CL-TR-45,
  author =	 {Sp{\"a}rck Jones, Karen},
  title = 	 {{Compound noun interpretation problems}},
  year = 	 1983,
  month = 	 jul,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-45.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This paper discusses the problems of compound noun
            	  interpretation in the context of automatic language
            	  processing. Given that compound processing implies
            	  identifying the senses of the words involved, determining
            	  their bracketing, and establishing their underlying
            	  semantic relations, the paper illustrates the need, even
            	  in comparatively favourable cases, for inference using
            	  pragmatic information. This has consequences for language
            	  processor architectures and, even more, for speech
            	  processors.},
  number = 	 {UCAM-CL-TR-45}
}

@TechReport{UCAM-CL-TR-46,
  author =	 {Garnett, Nicholas Henry},
  title = 	 {{Intelligent network interfaces}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-46}
}

@TechReport{UCAM-CL-TR-47,
  author =	 {Tait, John Irving},
  title = 	 {{Automatic summarising of English texts}},
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-47.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This thesis describes a computer program called Scrabble
            	  which can summarise short English texts. It uses large
            	  bodies of predictions about the likely contents of texts
            	  about particular topics to identify the commonplace
            	  material in an input text. Pre-specified summary
            	  templates, each associated with a different topic are
            	  used to condense the commonplace material in the input.
            	  Filled-in summary templates are then used to form a
            	  framework into which unexpected material in the input may
            	  be fitted, allowing unexpected material to appear in
            	  output summary texts in an essentially unreduced form.
            	  The system's summaries are in English.
            	  
            	  The program is based on technology not dissimilar to a
            	  script applier. However, Scrabble represents a
            	  significant advance over previous script-based
            	  summarising systems. It is much less likely to produce
            	  misleading summaries of an input text than some previous
            	  systems and can operate with less information about the
            	  subject domain of the input than others.
            	  
            	  These improvements are achieved by the use of three main
            	  novel ideas. First, the system incorporates a new method
            	  for identifying the idea or topics of an input text.
            	  Second, it allows a section of text to have more than one
            	  topic at a time, or at least a composite topic which may
            	  be dealt with by the computer program simultaneously
            	  applying the text predictions associated with more than
            	  one simple topic. Third, Scrabble incorporates new
            	  mechanisms for the incorporation of unexpected material
            	  in the input into its output summary texts. The
            	  incorporation of such material in the output summary is
            	  motivated by the view that it is precisely unexpected
            	  material which is likely to form the most salient matter
            	  in the input text.
            	  
            	  The performance of the system is illustrated by means of
            	  a number of example input texts and their Scrabble
            	  summaries.},
  number = 	 {UCAM-CL-TR-47}
}

@TechReport{UCAM-CL-TR-48,
  author =	 {Alshawi, Hiyan},
  title = 	 {{A mechanism for the accumulation and application of
         	   context in text processing}},
  year = 	 1983,
  month = 	 nov,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-48.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The paper describes a mechanism for the representation
            	  and application of context information for automatic
            	  natural language processing systems. Context information
            	  is gathered gradually during the reading of the text, and
            	  the mechanism gives a way of combining the effect of
            	  several different types of context factors. Context
            	  factors can be managed independently, while still
            	  allowing efficient access to entities in focus. The
            	  mechanism is claimed to be more general than the global
            	  focus mechanism used by Grosz for discourse
            	  understanding. Context affects the interpretation process
            	  by choosing the results, and restricting the processing,
            	  of a number of important language interpretation
            	  operations, including lexical disambiguation and
            	  reference resolution. The types of context factors that
            	  have been implemented in an experimental system are
            	  described, and examples of the application of context are
            	  given.},
  number = 	 {UCAM-CL-TR-48}
}

@TechReport{UCAM-CL-TR-49,
  author =	 {Matthews, David Charles James},
  title = 	 {{Programming language design with polymorphism}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-49}
}

@TechReport{UCAM-CL-TR-50,
  author =	 {Paulson, Lawrence},
  title = 	 {{Verifying the unification algorithm in LCF}},
  year = 	 1984,
  month = 	 mar,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-50.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Manna and Waldinger's theory of substitutions and
            	  unification has been verified using the Cambridge LCF
            	  theorem prover. A proof of the monotonicity of
            	  substitution is presented in detail, as an example of
            	  interaction with LCF. Translating the theory into LCF's
            	  domain-theoretic logic is largely straightforward.
            	  Well-founded induction on a complex ordering is
            	  translated into nested structural inductions. Correctness
            	  of unification is expressed using predicates for such
            	  properties as idempotence and most-generality. The
            	  verification is presented as a series of lemmas. The LCF
            	  proofs are compared with the original ones, and with
            	  other approaches. It appears difficult to find a logic
            	  that is both simple and flexible, especially for proving
            	  termination.},
  number = 	 {UCAM-CL-TR-50}
}

@TechReport{UCAM-CL-TR-51,
  author =	 {Winskel, Glynn and Larsen, Kim Guldstrand},
  title = 	 {{Using information systems to solve recursive domain
         	   equations effectively}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-51}
}

@TechReport{UCAM-CL-TR-52,
  author =	 {Temple, Steven},
  title = 	 {{The design of a ring communication network}},
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-52.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This dissertation describes the design of a high speed
            	  local area network. Local networks have been in use now
            	  for over a decade and there is a proliferation of
            	  different systems, experimental ones which are not widely
            	  used and commercial ones installed in hundreds of
            	  locations. For a new network design to be of interest
            	  from the research point of view it must have a feature or
            	  features which set it apart from existing networks and
            	  make it an improvement over existing systems. In the case
            	  of the network described, the research was started to
            	  produce a network which was considerably faster than
            	  current designs, but which retained a high degree of
            	  generality.
            	  
            	  As the research progressed, other features were
            	  considered, such as ways to reduce the cost of the
            	  network and the ability to carry data traffic of many
            	  different types. The emphasis on high speed is still
            	  present but other aspects were considered and are
            	  discussed in the dissertation. The network has been named
            	  the Cambridge Fast Ring and and the network hardware is
            	  currently being implemented as an integrated circuit at
            	  the University of Cambridge Computer Laboratory.
            	  
            	  The aim of the dissertation is to describe the background
            	  to the design and the decisions which were made during
            	  the design process, as well as the design itself. The
            	  dissertation starts with a survey of the uses of local
            	  area networks and examines some established networks in
            	  detail. It then proceeds by examining the characteristics
            	  of a current network installation to assess what is
            	  required of the network in that and similar applications.
            	  The major design considerations for a high speed network
            	  controller are then discussed and a design is presented.
            	  Finally, the design of computer interfaces and protocols
            	  for the network is discussed.},
  number = 	 {UCAM-CL-TR-52}
}

@TechReport{UCAM-CL-TR-53,
  author =	 {Fairbairn, Jon},
  title = 	 {{A new type-checker for a functional language}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-53}
}

@TechReport{UCAM-CL-TR-54,
  author =	 {Paulson, Lawrence},
  title = 	 {{Lessons learned from LCF}},
  year = 	 1984,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-54}
}

@TechReport{UCAM-CL-TR-55,
  author =	 {Moszkowski, Ben},
  title = 	 {{Executing temporal logic programs}},
  year = 	 1984,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-55}
}

@TechReport{UCAM-CL-TR-56,
  author =	 {Stoye, William},
  title = 	 {{A new scheme for writing functional operating systems}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-56}
}

@TechReport{UCAM-CL-TR-57,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{Constructing recursion operators in intuitionistic type
         	   theory}},
  year = 	 1984,
  month = 	 oct,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-57.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Martin-L{\"o}f's Intuitionistic Theory of Types is
            	  becoming popular for formal reasoning about computer
            	  programs. To handle recursion schemes other than
            	  primitive recursion, a theory of well-founded relations
            	  is presented. Using primitive recursion over higher
            	  types, induction and recursion are formally derived for a
            	  large class of well-founded relations. Included are $<$
            	  on natural numbers, and relations formed by inverse
            	  images, addition, multiplication, and exponentiation of
            	  other relations. The constructions are given in full
            	  detail to allow their use in theorem provers for Type
            	  Theory, such as Nuprl. The theory is compared with work
            	  in the field of ordinal recursion over higher types.},
  number = 	 {UCAM-CL-TR-57}
}

@TechReport{UCAM-CL-TR-58,
  author =	 {Winskel, Glynn},
  title = 	 {{Categories of models for concurrency}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-58}
}

@TechReport{UCAM-CL-TR-59,
  author =	 {Winskel, Glynn},
  title = 	 {{On the composition and decomposition of assertions}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-59}
}

@TechReport{UCAM-CL-TR-60,
  author =	 {Alshawi, Hiyan},
  title = 	 {{Memory and context mechanisms for automatic text
         	   processing}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-60}
}

@TechReport{UCAM-CL-TR-61,
  author =	 {Sp{\"a}rck Jones, Karen},
  title = 	 {{User models and expert systems}},
  year = 	 1984,
  month = 	 dec,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-61}
}

@TechReport{UCAM-CL-TR-62,
  author =	 {Robson, Michael},
  title = 	 {{Constraint enforcement in a relational database management
         	   system}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-62}
}

@TechReport{UCAM-CL-TR-63,
  author =	 {Matthews, David C.J.},
  title = 	 {{Poly manual}},
  year = 	 1985,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-63}
}

@TechReport{UCAM-CL-TR-64,
  author =	 {Boguraev, Branimir K. and Sp{\"a}rck Jones, Karen},
  title = 	 {{A framework for inference in natural language front ends
         	   to databases}},
  year = 	 1985,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-64}
}

@TechReport{UCAM-CL-TR-65,
  author =	 {Tillotson, Mark},
  title = 	 {{Introduction to the programming language ``Ponder''}},
  year = 	 1985,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-65}
}

@TechReport{UCAM-CL-TR-66,
  author =	 {Gordon, M.J.C. and Herbert, J.},
  title = 	 {{A formal hardware verification methodology and its
         	   application to a network interface chip}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-66}
}

@TechReport{UCAM-CL-TR-67,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{Natural deduction theorem proving via higher-order
         	   resolution}},
  year = 	 1985,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-67}
}

@TechReport{UCAM-CL-TR-68,
  author =	 {Gordon, Mike},
  title = 	 {{HOL : A machine oriented formulation of higher order logic}},
  year = 	 1985,
  month = 	 jul,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-68}
}

@TechReport{UCAM-CL-TR-69,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{Proving termination of normalization functions for
         	   conditional expressions}},
  year = 	 1985,
  month = 	 jun,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-69.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Boyer and Moore have discussed a recursive function that
            	  puts conditional expressions into normal form. It is
            	  difficult to prove that this function terminates on all
            	  inputs. Three termination proofs are compared: (1) using
            	  a measure function, (2) in domain theory using LCF, (3)
            	  showing that its ``recursion relation'', defined by the
            	  pattern of recursive calls, is well-founded. The last two
            	  proofs are essentially the same though conducted in
            	  markedly different logical frameworks. An obviously total
            	  variant of the normalize function is presented as the
            	  `computational meaning' of those two proofs.
            	  
            	  A related function makes nested recursive calls. The
            	  three termination proofs become more complex: termination
            	  and correctness must be proved simultaneously. The
            	  recursion relation approach seems flexible enough to
            	  handle subtle termination proofs where previously domain
            	  theory seemed essential.},
  number = 	 {UCAM-CL-TR-69}
}

@TechReport{UCAM-CL-TR-70,
  author =	 {Hamilton, Kenneth Graham},
  title = 	 {{A remote procedure call system}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-70}
}

@TechReport{UCAM-CL-TR-71,
  author =	 {Moszkowski, Ben},
  title = 	 {{Executing temporal logic programs}},
  year = 	 1985,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-71}
}

@TechReport{UCAM-CL-TR-72,
  author =	 {Clocksin, W.F.},
  title = 	 {{Logic programming and the specification of circuits}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-72}
}

@TechReport{UCAM-CL-TR-73,
  author =	 {Craft, Daniel Hammond},
  title = 	 {{Resource management in a distributed computing system}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-73}
}

@TechReport{UCAM-CL-TR-74,
  author =	 {Gordon, Mike},
  title = 	 {{Hardware verification by formal proof}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-74}
}

@TechReport{UCAM-CL-TR-75,
  author =	 {Fairbairn, Jon},
  title = 	 {{Design and implementation of a simple typed language based
         	   on the lambda-calculus}},
  year = 	 1985,
  month = 	 may,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-75.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Despite the work of Landin and others as long ago as
            	  1966, almost all recent programming languages are large
            	  and difficult to understand. This thesis is a
            	  re-examination of the possibility of designing and
            	  implementing a small but practical language based on very
            	  few primitive constructs.
            	  
            	  The text records the syntax and informal semantics of a
            	  new language called Ponder. The most notable features of
            	  the work are a powerful type-system and an efficient
            	  implementation of normal order reduction.
            	  
            	  In contrast to Landin's ISWIM, Ponder is statically
            	  typed, an expedient that increases the simplicity of the
            	  language by removing the requirement that operations must
            	  be defined for incorrect arguments. The type system is a
            	  powerful extension of Milner's polymorphic type system
            	  for ML in that it allows local quantification of types.
            	  This extension has the advantage that types that would
            	  otherwise need to be primitive may be defined.
            	  
            	  The criteria for the well-typedness of Ponder programmes
            	  are presented in the form of a natural deduction system
            	  in terms of a relation of generality between types. A new
            	  type checking algorithm derived from these rules is
            	  proposed.
            	  
            	  Ponder is built on the $\lambda$-calculus without the
            	  need for additional computation rules. In spite of this
            	  abstract foundation an efficient implementation based on
            	  Hughes' super-combinator approach is described. Some
            	  evidence of the speed of Ponder programmes is included.
            	  
            	  The same strictures have been applied to the design of
            	  the syntax of Ponder, which, rather than having many
            	  pre-defined clauses, allows the addition of new
            	  constructs by the use of a simple extension mechanism.},
  number = 	 {UCAM-CL-TR-75}
}

@TechReport{UCAM-CL-TR-76,
  author =	 {Cooper, R.C.B. and Hamilton, K.G.},
  title = 	 {{Preserving abstraction in concurrent programming}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-76}
}

@TechReport{UCAM-CL-TR-77,
  author =	 {Gordon, Mike},
  title = 	 {{Why higher-order logic is a good formalisation for
         	   specifying and verifying hardware}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-77}
}

@TechReport{UCAM-CL-TR-78,
  author =	 {Winskel, Glynn},
  title = 	 {{A complete proof system for SCCS with model assertions}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-78}
}

@TechReport{UCAM-CL-TR-79,
  author =	 {Winskel, Glynn},
  title = 	 {{Petri nets, algebras and morphisms}},
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-79.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {It is shown how a category of Petri nets can be viewed
            	  as a subcategory of two sorted algebras over multisets.
            	  This casts Petri nets in a familiar framework and
            	  provides a useful idea of morphism on nets different from
            	  the conventional definition -- the morphisms here respect
            	  the behaviour of nets. The categorical constructions with
            	  result provide a useful way to synthesise nets and reason
            	  about nets in terms of their components; for example
            	  various forms of parallel composition of Petri nets arise
            	  naturally from the product in the category. This abstract
            	  setting makes plain a useful functor from the category of
            	  Petri nets to a category of spaces of invariants and
            	  provides insight into the generalisations of the basic
            	  definition of Petri nets -- for instance the coloured and
            	  higher level nets of Kurt Jensen arise through a simple
            	  modificationof the sorts of the algebras underlying nets.
            	  Further it provides a smooth formal relation with other
            	  models of concurrency such as Milner's Calculus of
            	  Communicating Systems (CCS) and Hoare's Communicating
            	  Sequential Processes (CSP).},
  number = 	 {UCAM-CL-TR-79}
}

@TechReport{UCAM-CL-TR-80,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{Interactive theorem proving with Cambridge LCF : A user's
         	   manual}},
  year = 	 1985,
  month = 	 nov,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-80}
}

@TechReport{UCAM-CL-TR-81,
  author =	 {Stoye, William Robert},
  title = 	 {{The implementation of functional languages using custom
         	   hardware}},
  year = 	 1985,
  month = 	 dec,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-81.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {In recent years functional programmers have produced a
            	  great many good ideas but few results. While the use of
            	  functional languages has been enthusiastically advocated,
            	  few real application areas have been tackled and so the
            	  functional programmer's views and ideas are met with
            	  suspicion.
            	  
            	  The prime cause of this state of affairs is the lack of
            	  widely available, solid implementations of functional
            	  languages. This in turn stems from two major causes: (1)
            	  Our understanding of implementation techniques was very
            	  poor only a few years ago, and so any implementation that
            	  is ``mature'' is also likely to be unuseably slow. (2)
            	  While functional languages are excellent for expressing
            	  algorithms, there is still considerable debate in the
            	  functional programming community over the way in which
            	  input and output operations should be represented to the
            	  programmer. Without clear guiding principles implementors
            	  have tended to produce ad-hoc, inadequate solutions.
            	  
            	  My research is concerned with strengthening the case for
            	  functional programming. To this end I constructed a
            	  specialised processor, called SKIM, which could evaluate
            	  functional programs quickly. This allowed experimentation
            	  with various implementation methods, and provided a high
            	  performance implementation with which to experiment with
            	  writing large functional programs.
            	  
            	  This thesis describes the resulting work and includes the
            	  following new results: (1) Details of a practical
            	  turner-style combinator reduction implementation
            	  featuring greatly improved storage use compared with
            	  previous methods. (2) An implementation of Kennaway's
            	  director string idea that further enhances performance
            	  and increases understanding of a variety of reduction
            	  strategies. (3) Comprehensive suggestions concerning the
            	  representation of input, output, and nondeterministic
            	  tasks using functional languages, and the writing of
            	  operating systems. Details of the implementation of these
            	  suggestions developed on SKIM. (4) A number of
            	  observations concerning fuctional programming in general
            	  based on considerable practical experience.},
  number = 	 {UCAM-CL-TR-81}
}

@TechReport{UCAM-CL-TR-82,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{Natural deduction proof as higher-order resolution}},
  year = 	 1985,
  month = 	 dec,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-82.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {An interactive theorem prover, Isabelle, is under
            	  development. In LCF, each inference rule is represented
            	  by one function for forwards proof and another (a tactic)
            	  for backwards proof. In Isabelle, each inference rule is
            	  represented by a Horn clause. Resolution gives both
            	  forwards and backwards proof, supporting a large class of
            	  logics. Isabelle has been used to prove theorems in
            	  Martin-L{\"o}f's Constructive Type Theory.
            	  
            	  Quantifiers pose several difficulties: substitution,
            	  bound variables, Skolemization. Isabelle's representation
            	  of logical syntax is the typed lambda-calculus, requiring
            	  higher-order unification. It may have potential for logic
            	  programming. Depth-first search using inference rules
            	  constitutes a higher-order Prolog.},
  number = 	 {UCAM-CL-TR-82}
}

@TechReport{UCAM-CL-TR-83,
  author =	 {Wilson, Ian David},
  title = 	 {{Operation system design for large personal workstations}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-83}
}

@TechReport{UCAM-CL-TR-84,
  author =	 {Richards, Martin},
  title = 	 {{BSPL: a language for describing the behaviour of
         	   synchronous hardware}},
  year = 	 1986,
  month = 	 apr,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-84}
}

@TechReport{UCAM-CL-TR-85,
  author =	 {Winskel, Glynn},
  title = 	 {{Category theory and models for parallel computation}},
  year = 	 1986,
  month = 	 apr,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-85.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This report will illustrate two uses of category theory:
            	  Firstly the use of category theory to define semantics in
            	  a particular model. How semantic constructions can often
            	  be seen as categorical ones, and, in particular, how
            	  parallel compositions are derived from a categorical
            	  product and a nun-deterministic sum. These categorical
            	  notions can provide a basis for reasoning about
            	  computations and will be illustrated for the model of
            	  Petri nets.
            	  
            	  Secondly, the use of category theory to relate different
            	  semantics will be examined; specifically, how the
            	  relations between various concrete models like Petri
            	  nets, event structures, trees and state machines are
            	  expressed as adjunctions. This will be illustrated by
            	  showing the coreflection between safe Petri nets and
            	  trees.},
  number = 	 {UCAM-CL-TR-85}
}

@TechReport{UCAM-CL-TR-86,
  author =	 {Crawley, Stephen Christopher},
  title = 	 {{The Entity System: an object based filing system}},
  year = 	 1986,
  month = 	 apr,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-86}
}

@TechReport{UCAM-CL-TR-87,
  author =	 {Carter, Kathleen Anne},
  title = 	 {{Computer-aided type face design}},
  year = 	 1986,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-87}
}

@TechReport{UCAM-CL-TR-88,
  author =	 {Carter, David Maclean},
  title = 	 {{A shallow processing approach to anaphor resolution}},
  year = 	 1986,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-88}
}

@TechReport{UCAM-CL-TR-89,
  author =	 {Fairbairn, Jon},
  title = 	 {{Making form follow function : An exercise in functional
         	   programming style}},
  year = 	 1986,
  month = 	 jun,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-89.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The combined use of user-defined infix operators and
            	  higher order functions allows the programmer to invent
            	  new control structures tailored to a particular problem
            	  area.
            	  
            	  This paper is to suggest that such a combination has
            	  beneficial effects on the ease of both writing and
            	  reading programmes, and hence can increase programmer
            	  productivity. As an example, a parser for a simple
            	  language is presented in this style.
            	  
            	  It is hoped that the presentation will be palatable to
            	  people unfamiliar with the concepts of functional
            	  programming.},
  number = 	 {UCAM-CL-TR-89}
}

@TechReport{UCAM-CL-TR-90,
  author =	 {Hopper, Andy and Needham, Roger M.},
  title = 	 {{The Cambridge Fast Ring networking system (CFR)}},
  year = 	 1986,
  month = 	 jun,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-90}
}

@TechReport{UCAM-CL-TR-91,
  author =	 {Camilleri, Albert and Gordon, Mike and Melham, Tom},
  title = 	 {{Hardware verification using higher-order logic}},
  year = 	 1986,
  month = 	 sep,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-91.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The Hardware Verification Group at the University of
            	  Cambridge is investigating how various kinds of digital
            	  systems can be verified by mechanised formal proof. This
            	  paper explains our approach to representing behaviour and
            	  structure using higher order logic. Several examples are
            	  described including a ripple carry adder and a sequential
            	  device for computing the factorial function. The dangers
            	  of inaccurate models are illustrated with a CMOS
            	  exclusive-or gate.},
  number = 	 {UCAM-CL-TR-91}
}

@TechReport{UCAM-CL-TR-92,
  author =	 {Wray, Stuart Charles},
  title = 	 {{Implementation and programming techniques for functional
         	   languages}},
  year = 	 1986,
  month = 	 jun,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-92}
}

@TechReport{UCAM-CL-TR-93,
  author =	 {Bennett, J.P.},
  title = 	 {{Automated design of an instruction set for BCPL}},
  year = 	 1986,
  month = 	 jun,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-93}
}

@TechReport{UCAM-CL-TR-94,
  author =	 {Cohn, Avra and Gordon, Mike},
  title = 	 {{A mechanized proof of correctness of a simple counter}},
  year = 	 1986,
  month = 	 jun,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-94}
}

@TechReport{UCAM-CL-TR-95,
  author =	 {Winskel, Glynn},
  title = 	 {{Event structures : Lecture notes for the Advanced Course
         	   on Petri Nets}},
  year = 	 1986,
  month = 	 jul,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-95.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Event structures are a model of computational processes.
            	  They represent a process as a set of event occurrences
            	  with relations to express how events causally depend on
            	  others. This paper introduces event structures, shows
            	  their relationship to Scott domains and Petri nets, and
            	  surveys their role in denotational semantics, both for
            	  modelling laguages like CCS and CSP and languages with
            	  higher types.},
  number = 	 {UCAM-CL-TR-95}
}

@TechReport{UCAM-CL-TR-96,
  author =	 {Winskel, Glynn},
  title = 	 {{Models and logic of MOS circuits : Lectures for the
         	   Marktoberdorf Summerschool, August 1986}},
  year = 	 1986,
  month = 	 oct,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-96}
}

@TechReport{UCAM-CL-TR-97,
  author =	 {Mycroft, Alan},
  title = 	 {{A study on abstract interpretation and ``validating
         	   microcode algebraically''}},
  year = 	 1986,
  month = 	 oct,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-97}
}

@TechReport{UCAM-CL-TR-98,
  author =	 {Robinson, E.},
  title = 	 {{Power-domains, modalities and the Vietoris monad}},
  year = 	 1986,
  month = 	 oct,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-98.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {It is possible to divide the syntax-directed approaches
            	  to programming language semantics into two classes,
            	  ``denotational'', and ``proof-theoretic''. This paper
            	  argues for a different approach which also has the effect
            	  of linking the two methods. Drawing on recent work on
            	  locales as formal spaces we show that this provides a way
            	  in which we can hope to use a proof-theoretical semantics
            	  to give us a denotational one. This paper reviews aspects
            	  of the general theory, before developing a modal
            	  construction on locales and discussing the view of
            	  power-domains as free non-deterministic algebras.
            	  Finally, the relationship between the present work and
            	  that of Winskel is examined.},
  number = 	 {UCAM-CL-TR-98}
}

@TechReport{UCAM-CL-TR-99,
  author =	 {Matthews, David C.J.},
  title = 	 {{An overview of the Poly programming language}},
  year = 	 1986,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-99}
}

@TechReport{UCAM-CL-TR-100,
  author =	 {Joyce, Jeff and Birtwistle, Graham and Gordon, Mike},
  title = 	 {{Proving a computer correct in higher order logic}},
  year = 	 1986,
  month = 	 dec,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-100}
}

@TechReport{UCAM-CL-TR-101,
  author =	 {Milway, David Russel},
  title = 	 {{Binary routing networks}},
  year = 	 1986,
  month = 	 dec,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-101}
}

@TechReport{UCAM-CL-TR-102,
  author =	 {Matthews, David C.J.},
  title = 	 {{A persistent storage system for Poly and ML}},
  year = 	 1987,
  month = 	 jan,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-102}
}

@TechReport{UCAM-CL-TR-103,
  author =	 {Gordon, Mike},
  title = 	 {{HOL : A proof generating system for higher-order logic}},
  year = 	 1987,
  month = 	 jan,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-103}
}

@TechReport{UCAM-CL-TR-104,
  author =	 {Cohn, Avra},
  title = 	 {{A proof of correctness of the Viper microprocessor: the
         	   first level}},
  year = 	 1987,
  month = 	 jan,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-104.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The Viper microprocessor designed at the Royal Signals
            	  and Radar Establishment (RSRE) is one of the first
            	  commercially produced computers to have been developed
            	  using modern formal methods. Viper is specified in a
            	  sequence of decreasingly abstract levels. In this paper a
            	  mechanical proof of the equivalence of the first two of
            	  these levels is described. The proof was generated using
            	  a version of Robin Milner's LCF system.},
  number = 	 {UCAM-CL-TR-104}
}

@TechReport{UCAM-CL-TR-105,
  author =	 {Winskel, Glynn},
  title = 	 {{A compositional model of MOS circuits}},
  year = 	 1987,
  month = 	 apr,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-105}
}

@TechReport{UCAM-CL-TR-106,
  author =	 {Melham, Thomas F.},
  title = 	 {{Abstraction mechanisms for hardware verification}},
  year = 	 1987,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-106}
}

@TechReport{UCAM-CL-TR-107,
  author =	 {Coquand, Thierry and Gunter, Carl and Winskel, Glynn},
  title = 	 {{DI-domains as a model of polymorphism}},
  year = 	 1987,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-107}
}

@TechReport{UCAM-CL-TR-108,
  author =	 {Wilkes, Andrew John},
  title = 	 {{Workstation design for distributed computing}},
  year = 	 1987,
  month = 	 jun,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-108.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This thesis discusses some aspects of the design of
            	  computer systems for local area networks (LANs), with
            	  particular emphasis on the way such systems present
            	  themselves to their users. Too little attention to this
            	  issue frequently results in computing environments that
            	  cannot be extended gracefully to accommodate new hardware
            	  or software and do not present consistent, uniform
            	  interfaces to either their human users or their
            	  programmatic clients. Before computer systems can become
            	  truly ubiquitous tools, these problems of extensibility
            	  and accessibility must be solved. This dissertation
            	  therefore seeks to examine one possible approach,
            	  emphasising support for program development on LAN based
            	  systems.},
  number = 	 {UCAM-CL-TR-108}
}

@TechReport{UCAM-CL-TR-109,
  author =	 {Joyce, Jeffrey},
  title = 	 {{Hardware verification of VLSI regular structures}},
  year = 	 1987,
  month = 	 jul,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-109}
}

@TechReport{UCAM-CL-TR-110,
  author =	 {Winskel, Glynn},
  title = 	 {{Relating two models of hardware}},
  year = 	 1987,
  month = 	 jul,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-110}
}

@TechReport{UCAM-CL-TR-111,
  author =	 {Sp{\"a}rck Jones, K.},
  title = 	 {{Realism about user modelling}},
  year = 	 1987,
  month = 	 jun,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-111.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This paper reformulates the framework for user modelling
            	  presented in an earlier technical report, `User Models
            	  and Expert Systems', and considers the implications of
            	  the real limitations on the knowledge likely to be
            	  available to a system for the value and application of
            	  user models.},
  number = 	 {UCAM-CL-TR-111}
}

@TechReport{UCAM-CL-TR-112,
  author =	 {Wolfram, D.A.},
  title = 	 {{Reducing thrashing by adaptive backtracking}},
  year = 	 1987,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-112}
}

@TechReport{UCAM-CL-TR-113,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{The representation of logics in higher-order logic}},
  year = 	 1987,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-113}
}

@TechReport{UCAM-CL-TR-114,
  author =	 {Ades, Stephen},
  title = 	 {{An architecture for integrated services on the local area
         	   network}},
  year = 	 1987,
  month = 	 sep,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-114.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This dissertation concerns the provision of integrated
            	  services in a local area context, e.g. on business
            	  premises. The term integrated services can be understood
            	  at several levels. At the lowest, one network may be used
            	  to carry traffic of several media---voice, data, images
            	  etc. Above that, the telephone exchange may be replaced
            	  by a more versatile switching system, incorporating
            	  facilities such as stored voice messages. Its facilities
            	  may be accessible to the user through the interface of
            	  the workstation rather than a telephone. At a higher
            	  level still, new services such as multi-media document
            	  manipulation may be added to the capabilities of a
            	  workstation.
            	  
            	  Most of the work to date has been at the lowest of these
            	  levels, under the auspices of the Integrated Services
            	  Digital Network (ISDN), which mainly concerns wide area
            	  communications systems. The thesis presented here is that
            	  all of the above levels are important in a local area
            	  context. In an office environment, sophisticated data
            	  processing facilities in a workstation can usefully be
            	  combined with highly available telecommunications
            	  facilities such as the telephone, to offer the user new
            	  services which make the working day more pleasant and
            	  productive. That these facilities should be provided
            	  across one integrated network, rather than by several
            	  parallel single medium networks is an important
            	  organisational convenience to the system builder.
            	  
            	  The work described in this dissertation is relevant
            	  principally in a local area context---in the wide area
            	  economics and traffic balance dictate that the emphasis
            	  will be on only the network level of integration for some
            	  time now. The work can be split into three parts:
            	  
            	  i) the use of a packet network to carry mixed media. This
            	  has entailed design of packet voice protocols which
            	  produce delays low enough for the network to interwork
            	  with national telephone networks. The system has also
            	  been designed for minimal cost per
            	  telephone---packet-switched telephone systems have
            	  traditionally been more expensive than circuit-switched
            	  types. The network used as a foundation for this work has
            	  been the Cambridge Fast Ring.
            	  
            	  ii) use of techniques well established in distributed
            	  computing systems to build an `integrated services PABX
            	  (Private Automatic Branch Exchange)'. Current PABX
            	  designs have a very short life expectancy and an
            	  alarmingly high proportion of their costs is due to
            	  software. The ideas presented here can help with both of
            	  these problems, produce an extensible system and provide
            	  a basis for new multi-media services.
            	  
            	  iii) development of new user level Integrated Services.
            	  Work has been done in three areas. The first is
            	  multi-media documents. A voice editing interface is
            	  described along with the system structure required to
            	  support it. Secondly a workstation display has been built
            	  to support a variety of services based upon image
            	  manipulation and transmission. Finally techniques have
            	  been demonstrated by which a better interface to
            	  telephony functions can be provided to the user, using
            	  methods of control typical of workstation interfaces.},
  number = 	 {UCAM-CL-TR-114}
}

@TechReport{UCAM-CL-TR-115,
  author =	 {Dhingra, I.S.},
  title = 	 {{Formal validation of an integrated circuit design style}},
  year = 	 1987,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-115}
}

@TechReport{UCAM-CL-TR-116,
  author =	 {Coquand, Thierry and Gunter, Carl and Winskel, Glynn},
  title = 	 {{Domain theoretic models of polymorphism}},
  year = 	 1987,
  month = 	 sep,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-116}
}

@TechReport{UCAM-CL-TR-117,
  author =	 {Bacon, J.M. and Hamilton, K.G.},
  title = 	 {{Distributed computing with RPC: the Cambridge approach}},
  year = 	 1987,
  month = 	 oct,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-117.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The Cambridge Distributed Computing System (CDCS) is
            	  described and its evolution outlined. The Mayflower
            	  project allowed CDCS infrastructure, services and
            	  applications to be programmed in a high level, object
            	  oriented, language, Concurrent CLU. The Concurrent CLU
            	  RPC facility is described in detail. It is a
            	  non-transparent, type checked, type safe system which
            	  employs dynamic binding and passes objects of arbitrary
            	  graph structure. Recent extensions accomodate a number of
            	  languages and transport protocols. A comparison with
            	  other RPC schemes is given.},
  number = 	 {UCAM-CL-TR-117}
}

@TechReport{UCAM-CL-TR-118,
  author =	 {Boguraev, B.K. and Sp{\"a}rck Jones, K.},
  title = 	 {{Material concerning a study of cases}},
  year = 	 1987,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-118}
}

@TechReport{UCAM-CL-TR-119,
  author =	 {Cooper, Robert},
  title = 	 {{Pilgrim: a debugger for distributed systems}},
  year = 	 1987,
  month = 	 jul,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-119}
}

@TechReport{UCAM-CL-TR-120,
  author =	 {Wheeler, D.},
  title = 	 {{Block encryption}},
  year = 	 1987,
  month = 	 nov,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-120.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {A fast and simple way of encrypting computer data is
            	  needed. The UNIX crypt is a good way of doing this
            	  although the method is not cryptographically sound for
            	  text. The method suggested here is applied to larger
            	  blocks than the DES method which uses 64 bit blocks, so
            	  that the speed of encyphering is reasonable. The
            	  algorithm is designed for software rather than hardware.
            	  This forgoes two advantages of the crypt algorithm,
            	  namely that each character can be encoded and decoded
            	  independently of other characters and that the identical
            	  process is used both for encryption and decryption.
            	  However this method is better for coding blocks directly.},
  number = 	 {UCAM-CL-TR-120}
}

@TechReport{UCAM-CL-TR-121,
  author =	 {Billington, Jonathan},
  title = 	 {{A high-level petri net specification of the Cambridge Fast
         	   Ring M-access service}},
  year = 	 1987,
  month = 	 dec,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-121}
}

@TechReport{UCAM-CL-TR-122,
  author =	 {Herbert, John},
  title = 	 {{Temporal abstraction of digital designs}},
  year = 	 1988,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-122}
}

@TechReport{UCAM-CL-TR-123,
  author =	 {Herbert, John},
  title = 	 {{Case study of the Cambridge Fast Ring ECL chip using HOL}},
  year = 	 1988,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-123}
}

@TechReport{UCAM-CL-TR-124,
  author =	 {Herbert, John},
  title = 	 {{Formal verification of basic memory devices}},
  year = 	 1988,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-124}
}

@TechReport{UCAM-CL-TR-125,
  author =	 {Camilleri, Juanito},
  title = 	 {{An operational semantics for Occam}},
  year = 	 1988,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-125}
}

@TechReport{UCAM-CL-TR-126,
  author =	 {Leeser, M.E.},
  title = 	 {{Reasoning about the function and timing of integrated
         	   circuits with Prolog and temporal logic}},
  year = 	 1988,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-126}
}

@TechReport{UCAM-CL-TR-127,
  author =	 {Carroll, John and Boguraev, Bran and Grover, Claire and
          	  Briscoe, Ted},
  title = 	 {{A development environment for large natural language
         	   grammars}},
  year = 	 1988,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-127}
}

@TechReport{UCAM-CL-TR-128,
  author =	 {Cooper, Robert Charles Beaumont},
  title = 	 {{Debugging concurrent and distributed programs}},
  year = 	 1988,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-128}
}

@TechReport{UCAM-CL-TR-129,
  author =	 {Bennett, Jeremy Peter},
  title = 	 {{A methodology for automated design of computer instruction
         	   sets}},
  year = 	 1988,
  month = 	 mar,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-129.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {With semiconductor technology providing scope for
            	  increasingly complex computer architectures, there is a
            	  need more than ever to rationalise the methodology behind
            	  computer design. In the 1970's, byte stream architectures
            	  offered a rationalisation of computer design well suited
            	  to microcoded hardware. In the 1980's, RISC technology
            	  has emerged to simplify computer design and permit full
            	  advantage to be taken of very large scale integration.
            	  However, such approaches achieve their aims by
            	  simplifying the problem to a level where it is within the
            	  comprehension of a simple human being. Such an effort is
            	  not sufficient. There is a need to provide a methodology
            	  that takes the burden of design detail away from the
            	  human designer, leaving him free to cope with the
            	  underlying principles involved.
            	  
            	  In this dissertation I present a methodology for the
            	  design of computer instruction sets that is capable of
            	  automation in large part, removing the drudgery of
            	  individual instruction selection. The methodology does
            	  not remove the need for the designer's skill, but rather
            	  allows precise refinement of his ideas to obtain an
            	  optimal instruction set.
            	  
            	  In developing this methodology a number of pieces of
            	  software have been designed and implemented. Compilers
            	  have been written to generate trial instruction sets. An
            	  instruction set generator program has been written and
            	  the instruction set it proposes evaluated. Finally a
            	  prototype language for instruction set design has been
            	  devised and implemented.},
  number = 	 {UCAM-CL-TR-129}
}

@TechReport{UCAM-CL-TR-130,
  author =	 {Paulson, Lawrence C},
  title = 	 {{The foundation of a generic theorem prover}},
  year = 	 1988,
  month = 	 mar,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-130.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Isabelle is an interactive theorem prover that supports
            	  a variety of logics. It represents rules as propositions
            	  (not as functions) and builds proofs by combining rules.
            	  These operations constitute a meta-logic (or `logical
            	  framework') in which the object-logics are formalized.
            	  Isabelle is now based on higher-order logic -- a precise
            	  and well-understood foundation.
            	  
            	  Examples illustrate use of this meta-logic to formalize
            	  logics and proofs. Axioms for first-order logic are shown
            	  sound and complete. Backwards proof is formalized by
            	  meta-reasoning about object-level entailment.
            	  
            	  Higher-order logic has several practical advantages over
            	  other meta-logics. Many proof techniques are known, such
            	  as Huet's higher-order unification procedure.},
  number = 	 {UCAM-CL-TR-130}
}

@TechReport{UCAM-CL-TR-131,
  author =	 {Sp{\"a}rck Jones, Karen},
  title = 	 {{Architecture problems in the construction of expert
         	   systems for document retrieval}},
  year = 	 1986,
  month = 	 dec,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-131}
}

@TechReport{UCAM-CL-TR-132,
  author =	 {Leeser, Miriam Ellen},
  title = 	 {{Reasoning about the function and timing of integrated
         	   circuits with Prolog and temporal logic}},
  year = 	 1988,
  month = 	 apr,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-132}
}

@TechReport{UCAM-CL-TR-133,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{A preliminary users manual for Isabelle}},
  year = 	 1988,
  month = 	 may,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-133.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This is an early report on the theorem prover Isabelle
            	  and several of its object-logics. It describes Isabelle's
            	  operations, commands, data structures, and organization.
            	  This information is fairly low-level, but could benefit
            	  Isabelle users and implementors of other systems.},
  number = 	 {UCAM-CL-TR-133}
}

@TechReport{UCAM-CL-TR-134,
  author =	 {Cohn, Avra},
  title = 	 {{Correctness properties of the Viper black model: the
         	   second level}},
  year = 	 1988,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-134}
}

@TechReport{UCAM-CL-TR-135,
  author =	 {Melham, Thomas F.},
  title = 	 {{Using reclusive types to reason about hardware in higher
         	   order logic}},
  year = 	 1988,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-135}
}

@TechReport{UCAM-CL-TR-136,
  author =	 {Joyce, Jeffrey J.},
  title = 	 {{Formal specification and verification of asynchronous
         	   processes in higher-order logic}},
  year = 	 1988,
  month = 	 jun,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-136.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {We model the interaction of a synchronous process with
            	  an asynchronous memory process using a four-phase
            	  ``handshaking'' protocol. This example demonstrates the
            	  use of higher-order logic to reason about the behaviour
            	  of synchronous systems such as microprocessors which
            	  communicate requests to asynchronous devices and then
            	  wait for unpredictably long periods until these requests
            	  are answered. We also describe how our model could be
            	  revised to include some of the detailed timing
            	  requirements found in real systems such as the M68000
            	  microprocessor. One enhancement uses non-determinism to
            	  model minimum setup times for asynchronous inputs.
            	  Experience with this example suggests that higher-order
            	  logic may also be a suitable formalism for reasoning
            	  about more abstract forms of concurrency.},
  number = 	 {UCAM-CL-TR-136}
}

@TechReport{UCAM-CL-TR-137,
  author =	 {Hasle, F.V.},
  title = 	 {{Mass terms and plurals : From linguistic theory to natural
         	   language processing}},
  year = 	 1988,
  month = 	 jun,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-137}
}

@TechReport{UCAM-CL-TR-138,
  author =	 {Burrows, Michael and Abadi, Mart{\'\i}n and Needham, Roger},
  title = 	 {{Authentication: a practical study in belief and action}},
  year = 	 1988,
  month = 	 jun,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-138}
}

@TechReport{UCAM-CL-TR-139,
  author =	 {Manson, Paul R.},
  title = 	 {{Petri net theory: a survey}},
  year = 	 1988,
  month = 	 jun,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-139.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The intense interest in concurrent (or ``parallel'')
            	  computation over the past decade has given rise to a
            	  large number of languages for concurrent programming,
            	  representing many conflicting views of concurrency.
            	  
            	  The discovery that concurrent programming is
            	  significantly more difficult than sequential programming
            	  has prompted considerable research into determining a
            	  tractable and flexible theory of concurrency, with the
            	  aim of making concurrent processing more accessible, and
            	  indeed the wide variety of concurrent languages merely
            	  reflects the many different models of concurrency which
            	  have also been developed.
            	  
            	  This report, therefore introduces Petri nets, discussing
            	  their behaviour, interpretation and relationship to other
            	  models of concurrency. It defines and discusses several
            	  restrictions and extensions of the Petri net model,
            	  showing how they relate to basic Petri nets, while
            	  explaining why they have been of historical importance.
            	  Finally it presents a survey of the analysis methods
            	  applied to Petri nets in general and for some of the net
            	  models introduced here.},
  number = 	 {UCAM-CL-TR-139}
}

@TechReport{UCAM-CL-TR-140,
  author =	 {Camilleri, Albert John},
  title = 	 {{Executing behavioural definitions in higher-order logic}},
  year = 	 1988,
  month = 	 jul,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-140.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Over the past few years, computer scientists have been
            	  using formal verification techniques to show the
            	  correctness of digital systems. The verification process,
            	  however, is complicated and expensive. Even proofs of
            	  simple circuits can involve thousands of logical steps.
            	  Often it can be extremely difficult to find correct
            	  device specifications and it is desirable that one sets
            	  off to prove a correct specification from the start,
            	  rather than repeatedly backtrack from the verification
            	  process to modify the original definitions after
            	  discovering they were incorrect or inadequate.
            	  
            	  The main idea presented in the thesis is to amalgamate
            	  the techniques of simulation and verification, rather
            	  than have the latter replace the former. The result is
            	  that behavioural definitions can be simulated until one
            	  is reasonably sure that the specification is correct.
            	  Furthermore, proving the correctness with respect to
            	  these simulated specifications avoids the inadequacies of
            	  simulation where it may not be computationally feasible
            	  to demonstrate correctness by exhaustive testing.
            	  Simulation here has a different purpose: to get
            	  specifications correct as early as possible in the
            	  verification process. Its purpose is not to demonstrate
            	  the correctness of the implementation -- this is done in
            	  the verification stage when the very same specifications
            	  that were simulated are proved correct.
            	  
            	  The thesis discusses the implementation of an executable
            	  subset of the HOL logic, the version of Higher Order
            	  Logic embedded in the HOL theorem prover. It is shown
            	  that hardware can be effectively described using both
            	  relations and functions; relations being suitable for
            	  abstract specification and functions being suitable for
            	  execution. The difference between relational and
            	  functional specifications are discussed and illustrated
            	  by the verification of an n-bit adder. Techniques for
            	  executing functional specifications are presented and
            	  various optimisation strategies are shown which make the
            	  execution of the logic efficient. It is further shown
            	  that the process of generating optimised functional
            	  definitions from relational definitions can be automated.
            	  Example simulations of three hardware devices (a
            	  factorial machine, a small computer and a communications
            	  chip) are presented.},
  number = 	 {UCAM-CL-TR-140}
}

@TechReport{UCAM-CL-TR-141,
  author =	 {Want, Roy},
  title = 	 {{Reliable management of voice in a distributed system}},
  year = 	 1988,
  month = 	 jul,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-141.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The ubiquitous personal computer has found its way into
            	  most office environments. As a result, widespread use of
            	  the Local Area Network (LAN) for the purposes of sharing
            	  distributed computing resources has become common.
            	  Another technology, the Private Automatic Branch Exchange
            	  (PABX), has benefited from large research and development
            	  by the telephone companies. As a consequence, it is cost
            	  effective and has widely infiltrated the office world.
            	  Its primary purpose is to switch digitised voice but,
            	  with the growing need for communication between computers
            	  it is also being adapted to switch data. However, PABXs
            	  are generally designed around a centralised switch in
            	  which bandwidth is permanently divided between its
            	  subscribers. Computing requirements need much larger
            	  bandwidths and the ability to connect to several services
            	  at once, thus making the conventional PABX unsuitable for
            	  this application.
            	  
            	  Some LAN technologies are suitable for switching voice
            	  and data. The additional requirement for voice is that
            	  point to point delay for network packets should have a
            	  low upper-bound. The 10 Mb/s Cambridge Ring is an example
            	  of this type of network, but is relatively low bandwidth
            	  gives it limited application in this area. Networks with
            	  larger bandwidths (up to 100 Mb/s) are now becoming
            	  available comercially and could support a realistic
            	  population of clients requiring voice and data
            	  communication.
            	  
            	  Transporting voice and data in the same network has two
            	  main advantages. Firstly, from a practical point of view,
            	  wiring is minimised. Secondly, applications which
            	  integrate both media are made possible, and hence
            	  digitised voice may be controlled by client programs in
            	  new and interesting ways.
            	  
            	  In addition to the new applications, the original
            	  telephony facilities must also be available. They should,
            	  at least by default, appear to work in an identical way
            	  to our tried and trusted impression of a telephone.
            	  However, the control and management of a network
            	  telephone is now in the domain of distributed computing.
            	  The voice connections between telephones are virtual
            	  circuits. Control and data information can be freely
            	  mixed with voice at a network interface. The new problems
            	  that result are the management issues related to the
            	  distributed control of real-time media.
            	  
            	  This thesis describes the issues as a distributed
            	  computing problem and proposes solutions, many of which
            	  have been demonstrated in a real implementation.
            	  Particular attention has been paid to the quality of
            	  service provided by the solutions. This amounts to the
            	  design of helpful operator interfaces, flexible schemes
            	  for the control of voice from personal workstations and,
            	  in particular, a high reliability factor for the backbone
            	  telephony service. This work demonstrates the advantages
            	  and the practicality of integrating voice and data
            	  services within the Local Area Network.},
  number = 	 {UCAM-CL-TR-141}
}

@TechReport{UCAM-CL-TR-142,
  author =	 {Newman, Peter},
  title = 	 {{A fast packet switch for the integrated services backbone
         	   network}},
  year = 	 1988,
  month = 	 jul,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-142}
}

@TechReport{UCAM-CL-TR-143,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{Experience with Isabelle : A generic theorem prover}},
  year = 	 1988,
  month = 	 aug,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-143.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The theorem prover Isabelle is described briefly and
            	  informally. Its historical development is traced from
            	  Edinburgh LCF to the present day. The main issues are
            	  unification, quantifiers, and the representation of
            	  inference rules. The Edinburgh Logical Framework is also
            	  described, for a comparison with Isabelle. An appendix
            	  presents several Isabelle logics, including set theory
            	  and Constructive Type Theory, with examples of theorems.},
  number = 	 {UCAM-CL-TR-143}
}

@TechReport{UCAM-CL-TR-144,
  author =	 {Camilleri, Juanito},
  title = 	 {{An operational semantics for occam}},
  year = 	 1988,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-144}
}

@TechReport{UCAM-CL-TR-145,
  author =	 {Gordon, Michael J.C.},
  title = 	 {{Mechanizing programming logics in higher order logic}},
  year = 	 1988,
  month = 	 sep,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-145}
}

@TechReport{UCAM-CL-TR-146,
  author =	 {Melham, Thomas F.},
  title = 	 {{Automating recursive type definitions in higher order
         	   logic}},
  year = 	 1988,
  month = 	 sep,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-146}
}

@TechReport{UCAM-CL-TR-147,
  author =	 {Joyce, Jeffrey},
  title = 	 {{Formal specification and verification of microprocessor
         	   systems}},
  year = 	 1988,
  month = 	 sep,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-147}
}

@TechReport{UCAM-CL-TR-148,
  author =	 {Billington, Jonathan},
  title = 	 {{Extending coloured petri nets}},
  year = 	 1988,
  month = 	 sep,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-148.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Jensen's Coloured Petri Nets (CP-nets) are taken as the
            	  starting point for the development of a specification
            	  technique for complex concurrent systems. To increase its
            	  expressive power CP-nets are extended by including
            	  capacity and inhibitor functions. A class of extended
            	  CP-nets, known as P-nets, is defined that includes the
            	  capacity function and the threshold inhibitor extension.
            	  The inhibitor extension is defined in a totally
            	  symmetrical way to that of the usual pre place map (or
            	  incidence function). Thus the inhibitor and pre place
            	  maps may be equated by allowing a marking to be purged by
            	  a single transition occurrence, useful when specifying
            	  the abortion of various procedures. A chapter is devoted
            	  to developing the theory and notation for the purging of
            	  a place's marking or part of its marking.
            	  
            	  Two transformations from P-nets to CP-nets are presented
            	  and it is proved that they preserve interleaving
            	  behaviour. These are based on the notion of complementary
            	  places defined for PT-nets and involve the definition and
            	  proof of a new extended complementary place invariant for
            	  CP-nets
            	  
            	  The graphical form of P-nets, known as a P-Graph, is
            	  presented formally and draws upon the theories developed
            	  for algebraic specification. Arc inscriptions are
            	  multiples of tuples of terms generated by a many-sorted
            	  signature. Transition conditions are Boolean expressions
            	  derived from the same signature. An interpretation of the
            	  P-Graph is given in terms of a corresponding P-net. The
            	  work is similar to that of Vautherin but includes the
            	  inhibitor and capacity extension and a number of
            	  significant differences. in the P-Graph concrete sets are
            	  associated with places, rather than sorts and likewise
            	  there are concrete initial marking and capacity
            	  functions. Vautherin associates equations with
            	  transitions rather than the more general Boolean
            	  expressions. P-Graphs are useful for specification at a
            	  concrete level. Classes of the P-Graph, known as
            	  Many-sorted Algebraic Nets and Many-sorted
            	  Predicate/Transition nets, are defined and illustrated by
            	  a number of examples. An extended place capacity notation
            	  is developed to allow for the convenient representation
            	  of resource bounds in the graphical form.
            	  
            	  Some communications-oriented examples are presented
            	  including queues and the Demon Game of international
            	  standards fame.
            	  
            	  The report concludes with a discussion of future work. In
            	  particular, an abstract P-Graph is defined that is very
            	  similar to Vautherin's Petri net-like schema, but
            	  including the capacity and inhibitor extensions and
            	  associating boolean expressions with transitions. This
            	  will be useful for more abstract specifications (eg
            	  classes of communications protocols) and for their
            	  analysis.
            	  
            	  It is believed that this is the first coherent and formal
            	  presentation of these extensions in the literature.},
  number = 	 {UCAM-CL-TR-148}
}

@TechReport{UCAM-CL-TR-149,
  author =	 {Karger, Paul Ashley},
  title = 	 {{Improving security and performance of capability systems}},
  year = 	 1988,
  month = 	 oct,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-149.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This dissertation examines two major limitations of
            	  capability systems: an inability to support security
            	  policies that enforce confinement and a reputation for
            	  relatively poor performance when compared with
            	  non-capability systems.
            	  
            	  The dissertation examines why conventional capability
            	  systems cannot enforce confinement and proposes a new
            	  secure capability architecture, called SCAP, in which
            	  confinement can be enforced. SCAP is based on the earlier
            	  Cambridge Capability System, CAP. The dissertation shows
            	  how a non-discretionary security policy can be
            	  implemented on the new architecture, and how the new
            	  architecture can also be used to improve traceability of
            	  access and revocation of access.
            	  
            	  The dissertation also examines how capability systems are
            	  vulnerable to discretionary Trojan horse attacks and
            	  proposes a defence based on rules built into the
            	  command-language interpreter. System-wide garbage
            	  collection, commonly used in most capability systems, is
            	  examined in the light of the non-discretionary security
            	  policies and found to be fundamentally insecure. The
            	  dissertation proposes alternative approaches to storage
            	  management to provide at least some of the benefits of
            	  system-wide garbage collection, but without the
            	  accompanying security problems.
            	  
            	  Performance of capability systems is improved by two
            	  major techniques. First, the doctrine of programming
            	  generality is addressed as one major cause of poor
            	  performance. Protection domains should be allocated only
            	  for genuine security reasons, rather than at every
            	  subroutine boundary. Compilers can better enforce
            	  modularity and good programming style without adding the
            	  expense of security enforcement to every subroutine call.
            	  Second, the ideas of reduced instruction set computers
            	  (RISC) can be applied to capability systems to simplify
            	  the operations required. The dissertation identifies a
            	  minimum set of hardware functions needed to obtain good
            	  performance for a capability system. This set is much
            	  smaller than previous research had indicated necessary.
            	  
            	  A prototype implementation of some of the capability
            	  features is described. The prototype was implemented on a
            	  re-microprogrammed VAX-11/730 computer. The dissertation
            	  examines the performance and software compatibility
            	  implications of the new capability architecture, both in
            	  the context of conventional computers, such as the VAX,
            	  and in the context of RISC processors.},
  number = 	 {UCAM-CL-TR-149}
}

@TechReport{UCAM-CL-TR-150,
  author =	 {Camilleri, Albert John},
  title = 	 {{Simulation as an aid to verification using the HOL theorem
         	   prover}},
  year = 	 1988,
  month = 	 oct,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-150.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The HOL theorem proving system, developed by Mike Gordon
            	  at the University of Cambridge, is a mechanism of higher
            	  order logic, primarily intended for conducting formal
            	  proofs of digital system designs. In this paper we show
            	  that hardware specifications written in HOL logic can be
            	  executed to enable simulation as a means of supporting
            	  formal proof. Specifications of a small microprocessor
            	  are described, showing how HOL logic sentences can be
            	  transformed into executable code with minimum risk of
            	  introducing inconsistencies. A clean and effective
            	  optimisation strategy is recommended to make the
            	  executable specifications practical.},
  number = 	 {UCAM-CL-TR-150}
}

@TechReport{UCAM-CL-TR-151,
  author =	 {Dhingra, Inderpreel-Singh},
  title = 	 {{Formalising an integrated circuit design style in higher
         	   order logic}},
  year = 	 1988,
  month = 	 nov,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-151}
}

@TechReport{UCAM-CL-TR-152,
  author =	 {Pullen, Andrew Mark},
  title = 	 {{Motion development for computer animation}},
  year = 	 1988,
  month = 	 nov,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-152}
}

@TechReport{UCAM-CL-TR-153,
  author =	 {Burrows, Michael},
  title = 	 {{Efficient data sharing}},
  year = 	 1988,
  month = 	 dec,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-153.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {As distributed computing systems become widespread, the
            	  sharing of data between people using a large number of
            	  computers becomes more important. One of the most popular
            	  ways to facilitate this sharing is to provide a common
            	  file system, accessible by all the machines on the
            	  network. This approach is simple and reasonably
            	  effective, but the performance of the system can degrade
            	  significantly if the number of machines is increased. By
            	  using a hierarchical network, and arranging that machines
            	  typically access files stored in the same section of the
            	  network it is possible to build very large systems.
            	  However, there is still a limit on the number of machines
            	  that can share a single file server and a single network
            	  effectively.
            	  
            	  A good way to decrease network and server load is to
            	  cache file data on client machines, so that data need not
            	  be fetched from the centralized server each time it is
            	  accessed. This technique can improve the performance of a
            	  distributed file system and is used in a number of
            	  working systems. However, caching brings with it the
            	  overhead of maintaining consistency, or cache coherence.
            	  That is, each machine in the network must see the same
            	  data in its cache, even though one machine may be
            	  modifying the data as others are reading it. The problem
            	  is to maintain consistency without dramatically
            	  increasing the number of messages that must be passed
            	  between machines on the network.
            	  
            	  Some existing file systems take a probabilistic approach
            	  to consistency, some explicitly prevent the activities
            	  that can cause inconsistency, while others provide
            	  consistency only at the some cost in functionality or
            	  performance. In this dissertation, I examine how
            	  distributed file systems are typically used, and the
            	  degree to which caching might be expected to improve
            	  performance. I then describe a new file system that
            	  attempts to cache significantly more data than other
            	  systems, provides strong consistency guarantees, yet
            	  requires few additional messages for cache management.
            	  
            	  This new file-system provides fine-grain sharing of a
            	  file concurrently open on multiple machines on the
            	  network, at the granularity of a single byte. It uses a
            	  simple system of multiple-reader, single writer locks
            	  held in a centralized server to ensure cache consistency.
            	  The problem of maintaining client state in a centralized
            	  server are solved by using efficient data structures and
            	  crash recovery techniques.},
  number = 	 {UCAM-CL-TR-153}
}

@TechReport{UCAM-CL-TR-154,
  author =	 {Crabtree, I.B. and Crouch, R.S. and Moffat, D.C. and Pirie,
          	  N.J. and Pulman, S.G. and Ritchie, G.D. and Tate, B.A.},
  title = 	 {{A natural language interface to an intelligent planning
         	   system}},
  year = 	 1989,
  month = 	 jan,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-154}
}

@TechReport{UCAM-CL-TR-155,
  author =	 {Pulman, S.G. and Russell, G.J. and Ritchie, G.D. and Black,
          	  A.W.},
  title = 	 {{Computational morphology of English}},
  year = 	 1989,
  month = 	 jan,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-155.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This paper describes an implemented computer program
            	  which uses various kinds of linguistic knowledge to
            	  analyse existing or novel word forms in terms of their
            	  components. Three main types of knowledge are required
            	  (for English): knowledge about spelling or phonological
            	  changes consequent upon affixation (notice we are only
            	  dealing with isolated word forms); knowledge about the
            	  syntactic or semantic properties of affixation (i.e.
            	  inflexional and derivational morphology), and knowledge
            	  about the properties of the stored base forms of words
            	  (which in our case are always themselves words, rather
            	  than more abstract entities). These three types of
            	  information are stored as data files, represented in
            	  exactly the form a linguist might employ. These data
            	  files are then compiled by the system to produce a
            	  run-time program which will analyse arbitrary word forms
            	  presented to it in a way consistent with the original
            	  linguistic description.},
  number = 	 {UCAM-CL-TR-155}
}

@TechReport{UCAM-CL-TR-156,
  author =	 {Pulman, Steve},
  title = 	 {{Events and VP modifiers}},
  year = 	 1989,
  month = 	 jan,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-156}
}

@TechReport{UCAM-CL-TR-157,
  author =	 {Camilleri, Juanito},
  title = 	 {{Introducing a priority operator to CCS}},
  year = 	 1989,
  month = 	 jan,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-157}
}

@TechReport{UCAM-CL-TR-158,
  author =	 {Sp{\"a}rck Jones, Karen},
  title = 	 {{Tailoring output to the user: What does user modelling in
         	   generation mean?}},
  year = 	 1988,
  month = 	 aug,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-158.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This paper examines the implications for linguistic
            	  output generation tailored to the interactive system
            	  user, of earlier analyses of the components of user
            	  modelling and of the constraints realism imposes on
            	  modelling. Using a range of detailed examples it argues
            	  that tailoring based only on the actual dialogue and on
            	  the decision model required for the system task is quite
            	  adequate, and that more ambitious modelling is both
            	  dangerous and unnecessary.},
  number = 	 {UCAM-CL-TR-158}
}

@TechReport{UCAM-CL-TR-159,
  author =	 {Pitts, Andrew M.},
  title = 	 {{Non-trivial power types can't be subtypes of polymorphic
         	   types}},
  year = 	 1989,
  month = 	 jan,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-159.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-159}
}

@TechReport{UCAM-CL-TR-160,
  author =	 {Gordon, Andrew},
  title = 	 {{PFL+: A Kernal Scheme for Functions I/O}},
  year = 	 1989,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-160}
}

@TechReport{UCAM-CL-TR-161,
  author =	 {Matthews, D.C.J.},
  title = 	 {{Papers on Poly/ML}},
  year = 	 1989,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-161}
}

@TechReport{UCAM-CL-TR-162,
  author =	 {Glover, Claire and Briscoe, Ted and Carroll, John and
          	  Boguraev, Bran},
  title = 	 {{The Alvey natural language tools grammar (2nd Release)}},
  year = 	 1989,
  month = 	 apr,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-162}
}

@TechReport{UCAM-CL-TR-163,
  author =	 {Copestake, Ann and Sp{\"a}rck Jones, Karen},
  title = 	 {{Inference in a natural language front end for databases}},
  year = 	 1989,
  month = 	 feb,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-163.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This report describes the implementation and initial
            	  testing of knowledge representation and inference
            	  capabilities within a modular database front end designed
            	  for transportability.},
  number = 	 {UCAM-CL-TR-163}
}

@TechReport{UCAM-CL-TR-164,
  author =	 {Gong, Li and Wheeler, David J.},
  title = 	 {{A matrix key distribution system}},
  year = 	 1988,
  month = 	 oct,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-164.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {A new key distribution scheme is presented. It is based
            	  on the distinctive idea that lets each node have a set of
            	  keys of which it shares a distinct subset with every
            	  other node. This has the advantage that the numbers of
            	  keys that must be distributed and maintained are reduced
            	  by a square root factor; moreover, two nodes can start
            	  conversation with virtually no delay. Two versions of the
            	  scheme are given. Their performance and security analysis
            	  shows it is a practical solution to some key distribution
            	  problems.},
  number = 	 {UCAM-CL-TR-164}
}

@TechReport{UCAM-CL-TR-165,
  author =	 {Newman, Peter},
  title = 	 {{Fast packet switching for integrated services}},
  year = 	 1989,
  month = 	 mar,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-165}
}

@TechReport{UCAM-CL-TR-166,
  author =	 {Bacon, Jean},
  title = 	 {{Evolution of operating system structures}},
  year = 	 1989,
  month = 	 mar,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-166}
}

@TechReport{UCAM-CL-TR-167,
  author =	 {Joyce, Jeffrey J.},
  title = 	 {{A verified compiler for a verified microprocessor}},
  year = 	 1989,
  month = 	 mar,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-167}
}

@TechReport{UCAM-CL-TR-168,
  author =	 {Bacon, J.M. and Leslie, I.M. and Needham, R.M.},
  title = 	 {{Distributed computing with a processor bank}},
  year = 	 1989,
  month = 	 apr,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-168}
}

@TechReport{UCAM-CL-TR-169,
  author =	 {Seaborne, Andrew Franklin},
  title = 	 {{Filing in a heterogeneous network}},
  year = 	 1989,
  month = 	 apr,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-169}
}

@TechReport{UCAM-CL-TR-170,
  author =	 {Martin, Ursula and Nipkow, Tobias},
  title = 	 {{Ordered rewriting and confluence}},
  year = 	 1989,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-170}
}

@TechReport{UCAM-CL-TR-171,
  author =	 {Fairbairn, Jon},
  title = 	 {{Some types with inclusion properties in $\forall$,
         	   $\rightarrow$, $\mu$}},
  year = 	 1989,
  month = 	 jun,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-171.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This paper concerns the $\forall$, $\rightarrow$, $\mu$
            	  type system used in the non-strict functional programming
            	  language Ponder. While the type system is akin to the
            	  types of Second Order Lambda-calculus, the absence of
            	  type application makes it possible to construct types
            	  with useful inclusion relationships between them.
            	  
            	  To illustrate this, the paper contains definitions of a
            	  natural numbers type with many definable subtypes, and of
            	  a record type with inheritance.},
  number = 	 {UCAM-CL-TR-171}
}

@TechReport{UCAM-CL-TR-172,
  author =	 {Galliers, Julia Rose},
  title = 	 {{A theoretical framework for computer models of cooperative
         	   dialogue, acknowledging multi-agent conflict}},
  year = 	 1989,
  month = 	 jul,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-172}
}

@TechReport{UCAM-CL-TR-173,
  author =	 {Hale, Roger William Stephen},
  title = 	 {{Programming in temporal logic}},
  year = 	 1989,
  month = 	 jul,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-173}
}

@TechReport{UCAM-CL-TR-174,
  author =	 {Clarke, James Thomas Woodchurch},
  title = 	 {{General theory relating to the implementation of
         	   concurrent symbolic computation}},
  year = 	 1989,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-174}
}

@TechReport{UCAM-CL-TR-175,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{A formulation of the simple theory of types (for Isabelle)}},
  year = 	 1989,
  month = 	 aug,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-175.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Simple type theory is formulated for use with the
            	  generic theorem prover Isabelle. This requires explicit
            	  type inference rules. There are function, product, and
            	  subset types, which may be empty. Descriptions (the
            	  eta-operator) introduce the Axiom of Choice. Higher-order
            	  logic is obtained through reflection between formulae and
            	  terms of type bool. Recursive types and functions can be
            	  formally constructed.
            	  
            	  Isabelle proof procedures are described. The logic
            	  appears suitable for general mathematics as well as
            	  computational problems.},
  number = 	 {UCAM-CL-TR-175}
}

@TechReport{UCAM-CL-TR-176,
  author =	 {Clarke, T.J.W.},
  title = 	 {{Implementing aggregates in parallel functional languages}},
  year = 	 1989,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-176}
}

@TechReport{UCAM-CL-TR-177,
  author =	 {Noel, P.A.J.},
  title = 	 {{Experimenting with Isabelle in ZF Set Theory}},
  year = 	 1989,
  month = 	 sep,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-177}
}

@TechReport{UCAM-CL-TR-178,
  author =	 {Joyce, Jeffrey J.},
  title = 	 {{Totally verified systems: linking verified software to
         	   verified hardware}},
  year = 	 1989,
  month = 	 sep,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-178.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {We describe exploratory efforts to design and verify a
            	  compiler for a formally verified microprocessor as one
            	  aspect of the eventual goal of building totally verified
            	  systems. Together with a formal proof of correctness for
            	  the microprocessor this yields a precise and rigorously
            	  established link between the semantics of the source
            	  language and the execution of compiled code by the
            	  fabricated microchip. We describe in particular: (1) how
            	  the limitations of real hardware influenced this proof;
            	  and (2) how the general framework provided by higher
            	  order logic was used to formalize the compiler
            	  correctness problem for a hierarchically structured
            	  language.},
  number = 	 {UCAM-CL-TR-178}
}

@TechReport{UCAM-CL-TR-179,
  author =	 {Martin, Ursula and Nipkow, Tobias},
  title = 	 {{Automating Squiggol}},
  year = 	 1989,
  month = 	 sep,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-179}
}

@TechReport{UCAM-CL-TR-180,
  author =	 {Nipkow, Tobias},
  title = 	 {{Formal verification of data type refinement : Theory and
         	   practice}},
  year = 	 1989,
  month = 	 sep,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-180}
}

@TechReport{UCAM-CL-TR-181,
  author =	 {Nipkow, Tobias},
  title = 	 {{Proof transformations for equational theories}},
  year = 	 1989,
  month = 	 sep,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-181}
}

@TechReport{UCAM-CL-TR-182,
  author =	 {Levine, John M. and Fedder, Lee},
  title = 	 {{The theory and implementation of a bidirectional question
         	   answering system}},
  year = 	 1989,
  month = 	 oct,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-182}
}

@TechReport{UCAM-CL-TR-183,
  author =	 {Cardell-Oliver, Rachel},
  title = 	 {{The specification and verification of sliding window
         	   protocols in higher order logic}},
  year = 	 1989,
  month = 	 oct,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-183}
}

@TechReport{UCAM-CL-TR-184,
  author =	 {Tennenhouse, David Lawrence},
  title = 	 {{Site interconnection and the exchange architecture}},
  year = 	 1989,
  month = 	 oct,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-184}
}

@TechReport{UCAM-CL-TR-185,
  author =	 {Zhang, Guo Qiang},
  title = 	 {{Logics of Domains}},
  year = 	 1989,
  month = 	 dec,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-185}
}

@TechReport{UCAM-CL-TR-186,
  author =	 {McAuley, Derek Robert},
  title = 	 {{Protocol design for high speed networks}},
  year = 	 1990,
  month = 	 jan,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-186.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Improvements in fibre optic communication and in VLSI
            	  for network switching components have led to the
            	  consideration of building digital switched networks
            	  capable of providing point to point communication in the
            	  gigabit per second range. Provision of bandwidths of this
            	  magnitude allows the consideration of a whole new range
            	  of telecommunications services, integrating video, voice,
            	  image and text. These multi-service networks have a range
            	  of requirements not met by traditional network
            	  architectures designed for digital telephony or computer
            	  applications. This dissertation describes the design, and
            	  an implementation, of the Multi-Service Network
            	  architecture and protocol family, which is aimed at
            	  supporting these services.
            	  
            	  Asynchronous transfer mode networks provide the basic
            	  support required for these integrated services, and the
            	  Multi-Service Network architecture is designed primarily
            	  for these types of networks. The aim of the Multi-Service
            	  protocol family is to provide a complete architecture
            	  which allows use of the full facilities of asynchronous
            	  transfer mode networks by multi-media applications. To
            	  maintain comparable performance with the underlying
            	  media, certain elements of the MSN protocol stack are
            	  designed with implementation in hardware in mind. The
            	  interconnection of heterogeneous networks, and networks
            	  belonging to different security and administrative
            	  domains, is considered vital, so the MSN architecture
            	  takes an internetworking approach.},
  number = 	 {UCAM-CL-TR-186}
}

@TechReport{UCAM-CL-TR-187,
  author =	 {Copestake, Ann and Sp{\"a}rck Jones, Karen},
  title = 	 {{Natural language interfaces to databases}},
  year = 	 1989,
  month = 	 sep,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-187.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-187}
}

@TechReport{UCAM-CL-TR-188,
  author =	 {Leonard, Timothy E.},
  title = 	 {{Specification of computer architectures: a survey and
         	   annotated bibliography}},
  year = 	 1990,
  month = 	 jan,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-188}
}

@TechReport{UCAM-CL-TR-189,
  author =	 {Paulson, Lawrence C. and Nipkow, Tobias},
  title = 	 {{Isabelle tutorial and user's manual}},
  year = 	 1990,
  month = 	 jan,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-189.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This (obsolete!) manual describes how to use the theorem
            	  prover Isabelle. For beginners, it explains how to
            	  perform simple single-step proofs in the built-in logics.
            	  These include first-order logic, a classical sequent
            	  calculus, ZF set theory, Constructie Type Theory, and
            	  higher-order logic. Each of these logics is described.
            	  The manual then explains how to develop advanced tactics
            	  and tacticals and how to derive rules. Finally, it
            	  describes how to define new logics within Isabelle.},
  number = 	 {UCAM-CL-TR-189}
}

@TechReport{UCAM-CL-TR-190,
  author =	 {Copestake, Ann},
  title = 	 {{Some notes on mass terms and plurals}},
  year = 	 1990,
  month = 	 jan,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-190.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-190}
}

@TechReport{UCAM-CL-TR-191,
  author =	 {Nicolaou, Cosmos},
  title = 	 {{An architecture for real-time multimedia communications
         	   systems}},
  year = 	 1990,
  month = 	 feb,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-191.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {An architecture for real-time multimedia communications
            	  systems is presented. A multimedia communication systems
            	  includes both the communication protocols used to
            	  transport the real-time data and also the Distributed
            	  Computing system (DCS) within which any applications
            	  using these protocols must execute. The architecture
            	  presented attempts to integrate these protocols with the
            	  DCS in a smooth fashion in order to ease the writing of
            	  multimedia applications. Two issues are identified as
            	  being essential to the success of this integration:
            	  namely the synchronisation of related real-time data
            	  streams, and the management of heterogeneous multimedia
            	  hardware. The synchronisation problem is tackled by
            	  defining explicit synchronisation properties at the
            	  presentation level and by providing control and
            	  synchronisation operations within the DCS which operate
            	  in terms of these properties. The heterogeneity problems
            	  are addressed by separating the data transport semantics
            	  (protocols themselves) from the control semantics
            	  (protocol interfaces). The control semantics are
            	  implemented using a distributed, typed interface, scheme
            	  within the DCS (i.e. above the presentation layer),
            	  whilst the protocols themselves are implemented within
            	  the communication subsystem. The interface between the
            	  DCS and communications subsystem is referred to as the
            	  orchestration interface and can be considered to lie in
            	  the presentation and session layers.
            	  
            	  A conforming prototype implementation is currently under
            	  construction.},
  number = 	 {UCAM-CL-TR-191}
}

@TechReport{UCAM-CL-TR-192,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{Designing a theorem prover}},
  year = 	 1990,
  month = 	 may,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-192.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The methods and principles of theorem prover design are
            	  presented through an extended example. Starting with a
            	  sequent calculus for first-order logic, an automatic
            	  prover (called Folderol) is developed. Folderol can prove
            	  quite a few complicated theorems, although its search
            	  strategy is crude and limited. Folderol is coded in
            	  Standard ML and consists largely of pure functions. Its
            	  complete listing is included.
            	  
            	  The report concludes with a survey of other research in
            	  theorem proving: the Boyer/Moore theorem prover,
            	  Automath, LCF, and Isabelle.},
  number = 	 {UCAM-CL-TR-192}
}

@TechReport{UCAM-CL-TR-193,
  author =	 {Galliers, Julia Rose},
  title = 	 {{Belief revision and a theory of communication}},
  year = 	 1990,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-193}
}

@TechReport{UCAM-CL-TR-194,
  author =	 {Galliers, Julia Rose},
  title = 	 {{Proceedings of the First Belief Representation and Agent
         	   Architectures Workshop}},
  year = 	 1990,
  month = 	 mar,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-194}
}

@TechReport{UCAM-CL-TR-195,
  author =	 {Joyce, Jeffrey J.},
  title = 	 {{Multi-level verification of microprocessor-based systems}},
  year = 	 1990,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-195}
}

@TechReport{UCAM-CL-TR-196,
  author =	 {Van Tassell, John Peter},
  title = 	 {{The semantics of VHDL with Val and Hol: towards practical
         	   verification tools}},
  year = 	 1990,
  month = 	 jun,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-196}
}

@TechReport{UCAM-CL-TR-197,
  author =	 {Clarke, Thomas},
  title = 	 {{The semantics and implementation of aggregates : or : how
         	   to express concurrency without destroying determinism}},
  year = 	 1990,
  month = 	 jul,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-197}
}

@TechReport{UCAM-CL-TR-198,
  author =	 {Pitts, Andrew M.},
  title = 	 {{Evaluation Logic}},
  year = 	 1990,
  month = 	 aug,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-198.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-198}
}

@TechReport{UCAM-CL-TR-199,
  author =	 {Boulton, Richard and Gordon, Mike and Herbert, John and Van
          	  Tassel, John},
  title = 	 {{The HOL verification of ELLA designs}},
  year = 	 1990,
  month = 	 aug,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-199.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {HOL is a public domain system for generating proofs in
            	  higher order predicate calculus. It has been in
            	  experimental and commercial use in several countries for
            	  a number of years.
            	  
            	  ELLA is a hardware design language developed at the Royal
            	  Signals and Radar Establishment (RSRE) and marketed by
            	  Computer General Electronic Design. It supports
            	  simulation models at a variety of different abstraction
            	  levels.
            	  
            	  A preliminary methodology for reasoning about ELLA
            	  designs using HOL is described. Our approach is to
            	  semantically embed a subset of the ELLA language in
            	  higher order logic, and then to make this embedding
            	  convenient to use with parsers and pretty-printers. There
            	  are a number of semantic issues that may affect the ease
            	  of verification. We discuss some of these briefly. We
            	  also give a simple example to illustrate the methodology.},
  number = 	 {UCAM-CL-TR-199}
}

@TechReport{UCAM-CL-TR-200,
  author =	 {Nipkow, Tobias and Snelting, Gregor},
  title = 	 {{Type classes and overloading resolution via order-sorted
         	   unification}},
  year = 	 1990,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-200}
}

@TechReport{UCAM-CL-TR-201,
  author =	 {Melham, Thomas Frederick},
  title = 	 {{Formalizing abstraction mechanisms for hardware
         	   verification in higher order logic}},
  year = 	 1990,
  month = 	 aug,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-201.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Recent advances in microelectronics have given designers
            	  of digital hardware the potential to build devices of
            	  remarkable size and complexity. Along with this however,
            	  it becomes increasingly difficult to ensure that such
            	  systems are free from design errors, where complete
            	  simulation of even moderately sized circuits is
            	  impossible. One solution to these problems is that of
            	  hardware verification, where the functional behaviour of
            	  the hardware is described mathematically and formal proof
            	  is used to show that the design meets rigorous
            	  specifications of the intended operation.
            	  
            	  This dissertation therefore seeks to develop this,
            	  showing how reasoning about the correctness of hardware
            	  using formal proof can be achieved using fundamental
            	  abstraction mechanisms to relate specifications of
            	  hardware at different levels. Therefore a systematic
            	  method is described for defining any instance of a wide
            	  class of concrete data types in higher order logic. This
            	  process has been automated in the HOL theorem prover, and
            	  provides a firm logical basis for representing data in
            	  formal specifications.
            	  
            	  Further, these abstractions have been developed into a
            	  new technique for modelling the behaviour of entire
            	  classes of hardware designs. This is based on a formal
            	  representation in logic for the structure of circuit
            	  designs using the recursive types defined by the above
            	  method. Two detailed examples are presented showing how
            	  this work can be applied in practice.
            	  
            	  Finally, some techniques for temporal abstraction are
            	  explained, and the means for asserting the correctness of
            	  a model containing time-dependent behaviour is described.
            	  This work is then illustrated using a case study; the
            	  formal verification on HOL of a simple ring communication
            	  network.
            	  
            	  [Abstract by Nicholas Cutler (librarian), as none was
            	  submitted with the report.]},
  number = 	 {UCAM-CL-TR-201}
}

@TechReport{UCAM-CL-TR-202,
  author =	 {Harter, Andrew Charles},
  title = 	 {{Three-dimensional integrated circuit layout}},
  year = 	 1990,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-202}
}

@TechReport{UCAM-CL-TR-203,
  author =	 {de Paiva, Valeria C.V.},
  title = 	 {{Subtyping in Ponder (preliminary report)}},
  year = 	 1990,
  month = 	 aug,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-203.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This note starts the formal study of the type system of
            	  the functional language Ponder. Some of the problems of
            	  proving soundness and completeness are discussed and some
            	  preliminary results, about fragments of the type system,
            	  shown.
            	  
            	  It consists of 6 sections. In section 1 we review briefly
            	  Ponder's syntax and describe its typing system. In
            	  section 2 we consider a very restricted fragment of the
            	  language for which we can prove soundness of the type
            	  inference mechanism, but not completeness. Section 3
            	  describes possible models of this fragment and some
            	  related work. Section 4 describes the type-inference
            	  algorithm for a larger fragment of Ponder and in section
            	  5 we come up against some problematic examples. Section 6
            	  is a summary of further work.},
  number = 	 {UCAM-CL-TR-203}
}

@TechReport{UCAM-CL-TR-204,
  author =	 {Crole, Roy L. and Pitts, Andrew M.},
  title = 	 {{New foundations for fixpoint computations:
         	   FIX-hyperdoctrines and the FIX-logic}},
  year = 	 1990,
  month = 	 aug,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-204.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-204}
}

@TechReport{UCAM-CL-TR-205,
  author =	 {Paulson, Lawrence C. and Smith, Andrew W.},
  title = 	 {{Logic programming, functional programming and inductive
         	   definitions}},
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-205.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This paper reports an attempt to combine logic and
            	  functional programming. It also questions the traditional
            	  view that logic programming is a form of first-order
            	  logic, arguing instead that the essential nature of a
            	  logic program is an inductive definition. This revised
            	  view of logic programming suggests the design of a
            	  combined logic/functional language. A slow but working
            	  prototype is described.},
  number = 	 {UCAM-CL-TR-205}
}

@TechReport{UCAM-CL-TR-206,
  author =	 {Cardell-Oliver, Richard},
  title = 	 {{Formal verification of real-time protocols using higher
         	   order logic}},
  year = 	 1990,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-206}
}

@TechReport{UCAM-CL-TR-207,
  author =	 {Hawkins, Stuart Philip},
  title = 	 {{Video replay in computer animation}},
  year = 	 1990,
  month = 	 oct,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-207}
}

@TechReport{UCAM-CL-TR-208,
  author =	 {Ritter, Eike},
  title = 	 {{Categorical combinators for the calculus of constructions}},
  year = 	 1990,
  month = 	 oct,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-208}
}

@TechReport{UCAM-CL-TR-209,
  author =	 {Moore, Andrew William},
  title = 	 {{Efficient memory-based learning for robot control}},
  year = 	 1990,
  month = 	 nov,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-209.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This dissertation is about the application of machine
            	  learning to robot control. A system which has no initial
            	  model of the robot/world dynamics should be able to
            	  construct such a model using data received through its
            	  sensors---an approach which is formalized here as the SAB
            	  (State-Action-Behaviour) control cycle. A method of
            	  learning is presented in which all the experiences in the
            	  lifetime of the robot are explicitly remembered. The
            	  experiences are stored in a manner which permits fast
            	  recall of the closest previous experience to any new
            	  situation, thus permitting very quick predictions of the
            	  effects of proposed actions and, given a goal behaviour,
            	  permitting fast generation of a candidate action. The
            	  learning can take place in high-dimensional non-linear
            	  control spaces with real-valued ranges of variables.
            	  Furthermore, the method avoids a number of shortcomings
            	  of earlier learning methods in which the controller can
            	  become trapped in inadequate performance which does not
            	  improve. Also considered is how the system is made
            	  resistant to noisy inputs and how it adapts to
            	  environmental changes. A well founded mechanism for
            	  choosing actions is introduced which solves the
            	  experiment/perform dilemma for this domain with adequate
            	  computational efficiency, and with fast convergence to
            	  the goal behaviour. The dissertation explains in detail
            	  how the SAB control cycle can be integrated into both low
            	  and high complexity tasks. The methods and algorithms are
            	  evaluated with numerous experiments using both real and
            	  simulated robot domains. The final experiment also
            	  illustrates how a compound learning task can be
            	  structured into a hierarchy of simple learning tasks.},
  number = 	 {UCAM-CL-TR-209}
}

@TechReport{UCAM-CL-TR-210,
  author =	 {Nipkow, Tobias},
  title = 	 {{Higher-order unification, polymorphism, and subsorts}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-210}
}

@TechReport{UCAM-CL-TR-211,
  author =	 {Sp{\"a}rck Jones, Karen},
  title = 	 {{The role of artificial intelligence in information
         	   retrieval}},
  year = 	 1990,
  month = 	 nov,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-211}
}

@TechReport{UCAM-CL-TR-212,
  author =	 {Wrench, K.L.},
  title = 	 {{A distributed and-or parallel Prolog network}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-212}
}

@TechReport{UCAM-CL-TR-213,
  author =	 {de Paiva, Valeria Correa Vaz},
  title = 	 {{The Dialectica categories}},
  year = 	 1991,
  month = 	 jan,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-213.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This work consists of two main parts. The first one,
            	  which gives it its name, presents an internal categorical
            	  version of G{\"o}del's ``Dialectica interpretation'' of
            	  higher-order arithmetic. The idea is to analyse the
            	  Dialectica interpretation using a cetegory DC where
            	  objects are relations on objects of a basic category C
            	  and maps are pairs of maps of C satisfying a pullback
            	  condition. If C is finitely complete, DC exists and has a
            	  very natural symmetric monoidal structure. If C is
            	  locally cartesian closed then DC is symmetric monoidal
            	  closed. If we assume C with stable and disjoint
            	  coproducts, DC has cartesian products and weak-coproducts
            	  and satisfies a weak form of distributivity. Using the
            	  structure above, DC is a categorical model for
            	  intuitionistic linear logic.
            	  
            	  Moreover if C has free monoids then DC has cofree
            	  comonoids and the corresponding comonad ``!'' on DC,
            	  which has some special properties, can be used to model
            	  the exponential ``of course!'' in Intuitionistic Linear
            	  Logic. The category of ``!''-coalgebras is isomorphic to
            	  the category of comonoids in DC and, if we assume
            	  commutative monoids in C, the ``!''-Kleisli category,
            	  which is cartesian closed, corresponds to the Diller-Nahm
            	  variant of the Dialectica interpretation.
            	  
            	  The second part introduces the categories GC. The objects
            	  of GC are the same objects of DC, but morphisms are
            	  easier to handle, since they are maps in C in opposite
            	  directions. If C is finitely complete, the category GC
            	  exists. If C is cartesian closed, we can define a
            	  symmetric monoidal structure and if C is locally
            	  cartesian closed as well, we can define inernal homs in
            	  GC that make it a symmetric monoidal closed category.
            	  Supposing C with stable and disjoint coproducts, we can
            	  define cartesian products and coproducts in GC and, more
            	  interesting, we can define a dual operation to the tensor
            	  product bifunctor, called ``par''. The operation ``par''
            	  is a bifunctor and has a unit ``$\bot$'', which is a
            	  dualising object. Using the internal hom and $\bot$ we
            	  define a contravariant functor ``($-$)$\bot$'' which
            	  behaves like negation and thus it is used to model linear
            	  negation. We show that the category GC, with all the
            	  structure above, is a categorical model for Linear Logic,
            	  but not exactly the classical one.
            	  
            	  In the last chapter a comonad and a monad are defined to
            	  model the exponentials ``!'' and ``?''. To define these
            	  endofunctors, we use Beck's distributive laws in an
            	  interesting way. Finally, we show that the Kleisli
            	  category GC! is cartesian closed and that the categories
            	  DC and GC are related by a Kleisli construction.},
  number = 	 {UCAM-CL-TR-213}
}

@TechReport{UCAM-CL-TR-214,
  author =	 {Bradshaw, J.A. and Young, R.M.},
  title = 	 {{Integrating knowledge of purpose and knowledge of
         	   structure for design evaluation}},
  year = 	 1991,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-214}
}

@TechReport{UCAM-CL-TR-215,
  author =	 {Curzon, Paul},
  title = 	 {{A structured approach to the verification of low level
         	   microcode}},
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-215.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Errors in microprograms are especially serious since all
            	  higher level programs on the machine depend on the
            	  microcode. Formal verification presents one avenue which
            	  may be used to discover such errors. Previous systems
            	  which have been used for formally verifying microcode may
            	  be categorised by the form in which the microcode is
            	  supplied. Some demand that it be written in a high level
            	  microprogramming language. Conventional software
            	  verification techniques are then applied. Other methods
            	  allow the microcode to be supplied in the form of a
            	  memory image. It is treated as data to an interpreter
            	  modelling the behaviour of the microarchitecture. The
            	  proof is then performed by symbolic execution. A third
            	  solution is for the code to be supplied in an assembly
            	  language and modelled at that level. The assembler
            	  instructions are converted to commands in a modelling
            	  language. The resulting program is verified using
            	  traditional software verification techniques.
            	  
            	  In this dissertation I present a new universal
            	  microprogram verification system. It achieves many of the
            	  advantages of the other kinds of systems by adopting a
            	  hybrid approach. The microcode is supplied as a memory
            	  image, but it is transformed by the system to a high
            	  level program which may be verified using standard
            	  software verification techniques. The structure of the
            	  high level program is obtained from user supplied
            	  documentation. I show that this allows microcode to be
            	  split into small, independently validatable portions even
            	  when it was not written in that way. I also demonstrate
            	  that the techniques allow the complexity of detail due to
            	  the underlying microarchitecture to be controlled at an
            	  early stage in the validation process. I suggest that the
            	  system described would combine well with other validation
            	  tools and provide help throughout the firmware
            	  development cycle. Two case studies are given. The first
            	  describes the verification of Gordon's computer. This
            	  example being fairly simple, provides a good illustration
            	  of the techniques used by the system. The second case
            	  study is concerned with the High Level Hardware Orion
            	  computer which is a commercially produced machine with a
            	  fairly complex microarchitecture. This example shows that
            	  the techniques scale well to production
            	  microarchitectures.},
  number = 	 {UCAM-CL-TR-215}
}

@TechReport{UCAM-CL-TR-216,
  author =	 {Klein, Carole Susan},
  title = 	 {{Exploiting OR-parallelism in Prolog using multiple
         	   sequential machines}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-216}
}

@TechReport{UCAM-CL-TR-217,
  author =	 {Harita, Bhaskar Ramanathan},
  title = 	 {{Dynamic bandwidth management}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-217}
}

@TechReport{UCAM-CL-TR-218,
  author =	 {Nipkow, Tobias},
  title = 	 {{Higher-order critical pairs}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-218}
}

@TechReport{UCAM-CL-TR-219,
  author =	 {Leslie, Ian M. and McAuley, Derek M. and Hayter, Mark and
          	  Black, Richard and Beller, Reto and Newman, Peter and Doar,
          	  Matthew},
  title = 	 {{Fairisle project working documents : Snapshot 1}},
  year = 	 1991,
  month = 	 mar,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-219}
}

@TechReport{UCAM-CL-TR-220,
  author =	 {Nicolaou, Cosmos Andrea},
  title = 	 {{A distributed architecture for multimedia communication
         	   systems}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-220}
}

@TechReport{UCAM-CL-TR-221,
  author =	 {Milne, Robert},
  title = 	 {{Transforming axioms for data types into sequential
         	   programs}},
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-221.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {A process is proposed for refining specifications of
            	  abstract data types into efficient sequential
            	  implementations. The process needs little manual
            	  intervention. It is split into three stages, not all of
            	  which need always be carried out. The three stages entail
            	  interpreting equalities as behavioural equivalences,
            	  converting functions into procedures and replacing axioms
            	  by programs. The stages can be performed as automatic
            	  transformations which are certain to produce results that
            	  meet the specifications, provided that simple conditions
            	  hold. These conditions describe the adequacy of the
            	  specifications, the freedom from interference between the
            	  procedures, and the mode of construction of the
            	  procedures. Sufficient versions of these conditions can
            	  be checked automatically. Varying the conditions could
            	  produce implementations for different classes of
            	  specification. Though the transformations could be
            	  automated, the intermediate results, in styles of
            	  specification which cover both functions and procedures,
            	  have interest in their own right and may be particularly
            	  appropriate to object-oriented design.},
  number = 	 {UCAM-CL-TR-221}
}

@TechReport{UCAM-CL-TR-222,
  author =	 {Billington, Jonathan},
  title = 	 {{Extensions to coloured petri nets and their application to
         	   protocols}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-222}
}

@TechReport{UCAM-CL-TR-223,
  author =	 {Gladwin, Philip and Pulman, Stephen and Sp{\"a}rck Jones,
          	  Karen},
  title = 	 {{Shallow processing and automatic summarising: a first
         	   study}},
  year = 	 1991,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-223}
}

@TechReport{UCAM-CL-TR-224,
  author =	 {Briscoe, Ted and Carroll, John},
  title = 	 {{Generalised probabilistic LR parsing of natural language
         	   (corpora) with unification-based grammars}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-224}
}

@TechReport{UCAM-CL-TR-225,
  author =	 {de Paiva, Valeria},
  title = 	 {{Categorical multirelations, linear logic and petri nets
         	   (draft)}},
  year = 	 1991,
  month = 	 may,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-225.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This note presents a categorical treatment of
            	  multirelations, which is, in a loose sense a
            	  generalisation of both our previous work on the
            	  categories GC, and of Chu's construction A\_NC [Barr'79].
            	  The main motivation for writing this note was the
            	  utilisation of the category GC by Brown and Gurr [BG90]
            	  to model Petri nets. We wanted to extend their work to
            	  deal with multirelations, as Petri nets are usually
            	  modelled using multirelations pre and post. That proved
            	  easy enough and people interested mainly in concurrency
            	  theory should refer to our joint work [BGdP'91], this
            	  note deals with the mathematics underlying [BGdP'91]. The
            	  upshot of this work is that we build a model of
            	  Intuitionistic Linear Logic (without modalities) over any
            	  symmetric monoidal category C with a distinguished object
            	  (N, $\le$, $\circ$, e $-\circ$) -- a closed poset.
            	  Moreover, if the category C is cartesian closed with free
            	  monoids, we build a model of Intuitionistic Linear Logic
            	  with a non-trivial modality `!' over it.},
  number = 	 {UCAM-CL-TR-225}
}

@TechReport{UCAM-CL-TR-226,
  author =	 {Lam, Kwok-yan},
  title = 	 {{A new approach for improving system availability}},
  year = 	 1991,
  month = 	 jun,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-226}
}

@TechReport{UCAM-CL-TR-227,
  author =	 {Camilleri, Juanito Albert},
  title = 	 {{Priority in process calculi}},
  year = 	 1991,
  month = 	 jun,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-227}
}

@TechReport{UCAM-CL-TR-228,
  author =	 {Hayter, Mark and McAuley, Derek},
  title = 	 {{The desk area network}},
  year = 	 1991,
  month = 	 may,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-228.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {A novel architecture for use within an end computing
            	  system is described. This attempts to extend the concepts
            	  used in modern high speed networks into computer system
            	  design. A multimedia workstation is being built based on
            	  this concept to evaluate the approach.},
  number = 	 {UCAM-CL-TR-228}
}

@TechReport{UCAM-CL-TR-229,
  author =	 {Brown, David J.},
  title = 	 {{Abstraction of image and pixel : The thistle display
         	   system}},
  year = 	 1991,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-229}
}

@TechReport{UCAM-CL-TR-230,
  author =	 {Galliers, J.},
  title = 	 {{Proceedings of the second belief representation and agent
         	   architectures workshop (BRAA '91)}},
  year = 	 1991,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-230}
}

@TechReport{UCAM-CL-TR-231,
  author =	 {Yahalom, Raphael},
  title = 	 {{Managing the order of transactions in widely-distributed
         	   data systems}},
  year = 	 1991,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-231}
}

@TechReport{UCAM-CL-TR-232,
  author =	 {Corella, Francisco},
  title = 	 {{Mechanising set theory}},
  year = 	 1991,
  month = 	 jul,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-232.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Set theory is today the standard foundation of
            	  mathematics, but most proof development sysems (PDS) are
            	  based on type theory rather than set theory. This is due
            	  in part to the difficulty of reducing the rich
            	  mathematical vocabulary to the economical vocabulary of
            	  the set theory. It is known how to do this in principle,
            	  but traditional explanations of mathematical notations in
            	  set theoretic terms do not lead themselves easily to
            	  mechanical treatment.
            	  
            	  We advocate the representation of mathematical notations
            	  in a formal system consisting of the axioms of any
            	  version of ordinary set theory, such as ZF, but within
            	  the framework of higher-order logic with
            	  $\lambda$-conversion (H.O.L.) rather than first-order
            	  logic (F.O.L.). In this system each notation can be
            	  represented by a constant, which has a higher-order type
            	  when the notation binds variables. The meaning of the
            	  notation is given by an axiom which defines the
            	  representing constant, and the correspondence between the
            	  ordinary syntax of the notation and its representation in
            	  the formal language is specified by a rewrite rule. The
            	  collection of rewrite rules comprises a rewriting system
            	  of a kind which is computationally well behaved.
            	  
            	  The formal system is justified by the fact than set
            	  theory within H.O.L. is a conservative extension of set
            	  theory within F.O.L. Besides facilitating the
            	  representation of notations, the formal system is of
            	  interestbecause it permits the use of mathematical
            	  methods which do not seem to be available in set theory
            	  within F.O.L.
            	  
            	  A PDS, called Watson, has been built to demonstrate this
            	  approach to the mechanization of mathematics. Watson
            	  embodies a methodology for interactive proof which
            	  provides both flexibility of use and a relative guarantee
            	  of correctness. Results and proofs can be saved, and can
            	  be perused and modified with an ordinary text editor. The
            	  user can specify his own notations as rewrite rules and
            	  adapt the mix of notations to suit the problem at hand;
            	  it is easy to switch from one set of notations to
            	  another. As a case study, Watson has been used to prove
            	  the correctness of a latch implemented as two
            	  cross-coupled nor-gates, with an approximation of time as
            	  a continuum.},
  number = 	 {UCAM-CL-TR-232}
}

@TechReport{UCAM-CL-TR-233,
  author =	 {Carroll, John and Briscoe, Ted and Grover, Claire},
  title = 	 {{A development environment for large natural language
         	   grammars}},
  year = 	 1991,
  month = 	 jul,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-233}
}

@TechReport{UCAM-CL-TR-234,
  author =	 {Sp{\"a}rck Jones, Karen},
  title = 	 {{Two tutorial papers: Information retrieval \& Thesaurus}},
  year = 	 1991,
  month = 	 aug,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-234.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The first paper describes the characteristics of
            	  information retrieval from documents or texts, the
            	  development and status of automatic indexing and
            	  retrieval, and the actual and potential relations between
            	  information retrieval and artificial intelligence. The
            	  second paper discusses the properties, construction and
            	  actual and potential uses of thesauri, as semantic
            	  classifications or terminological knowledge bases, in
            	  information retrieval and natural language processing.},
  number = 	 {UCAM-CL-TR-234}
}

@TechReport{UCAM-CL-TR-235,
  author =	 {Wang, Heng},
  title = 	 {{Modelling and image generation}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-235}
}

@TechReport{UCAM-CL-TR-236,
  author =	 {Bradshaw, John Anthony},
  title = 	 {{Using knowledge of purpose and knowledge of structure as a
         	   basic for evaluating the behaviour of mechanical systems}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-236}
}

@TechReport{UCAM-CL-TR-237,
  author =	 {Bridge, Derek G.},
  title = 	 {{Computing presuppositions in an incremantal language
         	   processing system}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-237}
}

@TechReport{UCAM-CL-TR-238,
  author =	 {Briscoe, Ted and Copestake, Ann and de Paiva, Valeria},
  title = 	 {{Proceedings of the ACQUILEX workshop on default
         	   inheritance in the lexicon}},
  year = 	 1991,
  month = 	 oct,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-238}
}

@TechReport{UCAM-CL-TR-239,
  author =	 {Maybury, Mark Thomas},
  title = 	 {{Planning multisentential English text using communicative
         	   acts}},
  year = 	 1991,
  month = 	 dec,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-239.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The goal of this research is to develop explanation
            	  presentation mechanisms for knowledge based systems which
            	  enable them to define domain terminology and concepts,
            	  narrate events, elucidate plans, processes, or
            	  propositions and argue to support a claim or advocate
            	  action. This requires the development of devices which
            	  select, structure, order and then linguistically realize
            	  explanation content as coherent and cohesive English
            	  text.
            	  
            	  With the goal of identifying generic explanation
            	  presentation strategies, a wide range of naturally
            	  occurring texts were analyzed with respect to their
            	  communicative structure, function, content and intended
            	  effects on the reader. This motivated an integrated
            	  theory of communicative acts which characterizes text at
            	  the level of rhetorical acts (e.g. describe, define,
            	  narrate), illocutionary acts (e.g. inform, request), and
            	  locutionary acts (ask, command). Taken as a whole, the
            	  identified communicative acts characterize the structure,
            	  content and intended effects of four types of text:
            	  description, narration, exposition, argument. These text
            	  types have distinct effects such as getting the reader to
            	  know about entities, to know about events, to understand
            	  plans, processes, or propositions, or to believe
            	  propositions or want to perform actions. In addition to
            	  identifying the communicative function and effect of text
            	  at multiple levels of abstraction, this dissertation
            	  details a tripartite theory of focus of attention
            	  (discourse focus, temporal focus and spatial focus) which
            	  constrains the planning and linguistic realization of
            	  text.
            	  
            	  To test the integrated theory of communicative acts and
            	  tripartite theory of focus of attention, a text
            	  generation system TEXPLAN (Textual EXplanation PLANner)
            	  was implemented that plans and linguistically realizes
            	  multisentential and multiparagraph explanations from
            	  knowledge based systems. The communicative acts
            	  identified during text analysis were formalized over
            	  sixty compositional and (in some cases) recursive plan
            	  operators in the library of a hierarchical planner.
            	  Discourse, temporal and spatial models were implemented
            	  to track and use attentional information to guide the
            	  organization and realization of text. Because the plan
            	  operators distinguish between the communicative function
            	  (e.g. argue for a proposition) and the expected effect
            	  (e.g. the reader believes the proposition) of
            	  communicative acts, the system is able to construct a
            	  discourse model of the structure and function of its
            	  textual responses as well as a user model of the expected
            	  effects of its responses on the reader's knowledge,
            	  beliefs, and desires. The system uses both the discourse
            	  model and user model to guide subsequent utterances. To
            	  test its generality, the system was interfaced to a
            	  variety of domain applications including a
            	  neuropsychological diagnosis system, a mission planning
            	  system, and a knowledge based mission simulator. The
            	  system produces descriptions, narratives, expositions and
            	  arguments from these applications, thus exhibiting a
            	  broader ranger of rhetorical coverage then previous text
            	  generation systems.},
  number = 	 {UCAM-CL-TR-239}
}

@TechReport{UCAM-CL-TR-240,
  author =	 {Camilleri, Juanito},
  title = 	 {{Symbolic compilation and execution of programs by proof: a
         	   case study in HOL}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-240}
}

@TechReport{UCAM-CL-TR-241,
  author =	 {Vogel, Thomas Ulrich},
  title = 	 {{Learning in large state spaces with an application to
         	   biped robot walking}},
  year = 	 1991,
  month = 	 dec,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-241}
}

@TechReport{UCAM-CL-TR-242,
  author =	 {Mapp, Glenford Ezra},
  title = 	 {{An object oriented approach to virtual memory management}},
  year = 	 1992,
  month = 	 jan,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-242.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Advances in computer technology are being pooled
            	  together to form a new computing environment which is
            	  characterised by powerful workstations with vast amounts
            	  of memory connected to high speed networks. This
            	  environment will provide a large number of diverse
            	  services such as multimedia communications, expert
            	  systems and object-oriented databases. In order to
            	  develop these complex applications in an efficient
            	  manner, new interfaces are required which are simple,
            	  fast and flexible and allow the programmer to use an
            	  object-oriented approach throughout the design and
            	  implementation of an application. Virtual memory
            	  techniques are increasingly being used to build these new
            	  facilities.
            	  
            	  In addition since CPU speeds continue to increase faster
            	  than disk speeds, an I/O bottleneck may develop in which
            	  the CPU may be idle for long periods waiting for paging
            	  requests to be satisfied. To overcome this problem it is
            	  necessary to develop new paging algorithms that better
            	  reflect how different objects are used. Thus a facility
            	  to page objects on a per-object basis is required and a
            	  testbed is also needed to obtain experimental data on the
            	  paging activity of different objects.
            	  
            	  Virtual memory techniques, previously only used in
            	  mainframe and minicomputer architectures, are being
            	  employed in the memory management units of modern
            	  microprocessors. With very large address spaces becoming
            	  a standard feature of most systems, the use of memory
            	  mapping is seen as an effective way of providing greater
            	  flexibility as well as improved system efficiency.
            	  
            	  This thesis presents an object-oriented interface for
            	  memory mapped objects. Each object has a designated
            	  object type. Handles are associated with different object
            	  types and the interface allows users to define and manage
            	  new object types. Moving data between the object and its
            	  backing store is done by user-level processes called
            	  object managers. Object managers interact with the kernel
            	  via a specified interface thus allowing users to build
            	  their own object managers. A framework to compare
            	  different algorithms was also developed and an
            	  experimental testbed was designed to gather and analyse
            	  data on the paging activity of various programs. Using
            	  the testbed, conventional paging algorithms were applied
            	  to different types of objects and the results were
            	  compared. New paging algorithms were designed and
            	  implemented for objects that are accessed in a highly
            	  sequential manner.},
  number = 	 {UCAM-CL-TR-242}
}

@TechReport{UCAM-CL-TR-243,
  author =	 {Cawsey, Alison and Galliers, Julia and Reece, Stenev and
          	  Sp{\"a}rck Jones, Karen},
  title = 	 {{Automating the librarian: a fundamental approach using
         	   belief revision}},
  year = 	 1992,
  month = 	 jan,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-243}
}

@TechReport{UCAM-CL-TR-244,
  author =	 {Melham, T.F.},
  title = 	 {{A mechanized theory of the $\pi$-calculus in HOL}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-244}
}

@TechReport{UCAM-CL-TR-245,
  author =	 {Dixon, Michael J.},
  title = 	 {{System support for multi-service traffic}},
  year = 	 1992,
  month = 	 jan,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-245.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Digital network technology is now capable of supporting
            	  the bandwidth requirements of diverse applications such
            	  as voice, video and data (so called multi-service
            	  traffic). Some media, for example voice, have specific
            	  transmission requirements regarding the maximum packet
            	  delay and loss which they can tolerate. Problems arise
            	  when attempting to multiplex such traffic over a single
            	  channel. Traditional digital networks based on the
            	  Packet- (PTM) and Synchronous- (STM) Transfer Modes prove
            	  unsuitable due to their media access contention and
            	  inflexible bandwidth allocation properties respectively.
            	  The Asynchronous Transfer Mode (STM) has been proposed as
            	  a compromise between the PTM and STM techniques. The
            	  current state of multimedia research suggests that a
            	  significant amount of multi-service traffic will be
            	  handled by computer operating systems. Unfortunately
            	  conventional operating systems are largely unsuited to
            	  such a task. This dissertation is concerned with the
            	  system organisation necessary in order to extend the
            	  benefits of ATM networking through the endpoint operating
            	  system and up to the application level. A locally
            	  developed micro-kernel, with ATM network protocol
            	  support, has been used as a testbed for the ideas
            	  presented. Practical results over prototype ATM networks,
            	  including the 512 MHz Cambridge Backbone Network, are
            	  presented.},
  number = 	 {UCAM-CL-TR-245}
}

@TechReport{UCAM-CL-TR-246,
  author =	 {Poznanski, Victor},
  title = 	 {{A relevance-based utterance processing system}},
  year = 	 1992,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-246}
}

@TechReport{UCAM-CL-TR-247,
  author =	 {Crole, Roy Luis},
  title = 	 {{Programming metalogics with a fixpoint type}},
  year = 	 1992,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-247}
}

@TechReport{UCAM-CL-TR-248,
  author =	 {Boulton, Richard J.},
  title = 	 {{On efficiency in theorem provers which fully expand proofs
         	   into primitive inferences}},
  year = 	 1992,
  month = 	 feb,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-248.dvi.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Theorem Provers which fully expand proofs into
            	  applications of primitive inference rules can be made
            	  highly secure, but have been criticized for being orders
            	  of magnitude slower than many other theorem provers. We
            	  argue that much of this relative inefficiency is due to
            	  the way proof procedures are typically written and not
            	  all is inherent in the way the systems work. We support
            	  this claim by considering a proof procedure for linear
            	  arithmetic. We show that straightforward techniques can
            	  be used to significantly cut down the computation
            	  required. An order of magnitude improvement in the
            	  performance is shown by an implementation of these
            	  techniques.},
  number = 	 {UCAM-CL-TR-248}
}

@TechReport{UCAM-CL-TR-249,
  author =	 {Van Tassel, John P.},
  title = 	 {{A formalisation of the VHDL simulation cycle}},
  year = 	 1992,
  month = 	 mar,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-249.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The VHSIC Hardware Description Language (VHDL) has been
            	  gaining wide acceptance as a unifying HDL. It is,
            	  however, still a language in which the only way of
            	  validating a design is by careful simulation. With the
            	  aim of better understanding VHDL's particular simulation
            	  process and eventually reasoning about it, we have
            	  developed a formalisation of VHDL's simulation cycle for
            	  a subset of the language. It has also been possible to
            	  embed our semantics in the Cambridge Higher-Order Logic
            	  (HOL) system and derive interesting properties about
            	  specific VHDL programs.},
  number = 	 {UCAM-CL-TR-249}
}

@TechReport{UCAM-CL-TR-250,
  author =	 {Ferguson, Innes A.},
  title = 	 {{TouringMachines: autonomous agents with attitudes}},
  year = 	 1992,
  month = 	 apr,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-250.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-250}
}

@TechReport{UCAM-CL-TR-251,
  author =	 {Jiang, Xiaofeng},
  title = 	 {{Multipoint digital video communication}},
  year = 	 1992,
  month = 	 apr,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-251}
}

@TechReport{UCAM-CL-TR-252,
  author =	 {Pitts, Andrew M.},
  title = 	 {{A co-induction principle for recursively defined domains}},
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-252.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-252}
}

@TechReport{UCAM-CL-TR-253,
  author =	 {Sanfilippo, Antonio},
  title = 	 {{The (other) Cambridge ACQUILEX papers}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-253}
}

@TechReport{UCAM-CL-TR-254,
  author =	 {Boulton, Richard J.},
  title = 	 {{A HOL semantics for a subset of ELLA}},
  year = 	 1992,
  month = 	 apr,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-254.dvi.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Formal verification is an important tool in the design
            	  of computer systems, especially when the systems are
            	  safety or security critical. However, the formal
            	  techniques currently available are not well integrated
            	  into the set of tools more traditionally used by
            	  designers. This work is aimed at improving the
            	  integration by providing a formal semantics for a subset
            	  of the hardware description language ELLA, and by
            	  supporting this semantics in the HOL theorem proving
            	  system, which has been used extensively for hardware
            	  verification.
            	  
            	  A semantics for a subset of ELLA is described, and an
            	  outline of a proof of the equivalence of parallel and
            	  recursive implementations of an n-bit adder is given as
            	  an illustration of the semantics. The proof has been
            	  performed in an extension of the HOL system. Some proof
            	  tools written to support the verification are also
            	  described.},
  number = 	 {UCAM-CL-TR-254}
}

@TechReport{UCAM-CL-TR-255,
  author =	 {Cardell-Oliver, Rachel Mary},
  title = 	 {{The formal verification of hard real-time systems}},
  year = 	 1992,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-255}
}

@TechReport{UCAM-CL-TR-256,
  author =	 {Richards, Martin},
  title = 	 {{MCPL programming manual}},
  year = 	 1992,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-256}
}

@TechReport{UCAM-CL-TR-257,
  author =	 {Gor{\'e}, Rajeev Prakhakar},
  title = 	 {{Cut-free sequent and tableau systems for propositional
         	   normal modal logics}},
  year = 	 1992,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-257}
}

@TechReport{UCAM-CL-TR-258,
  author =	 {Greaves, David J. and McAuley, Derek},
  title = 	 {{Private ATM networks}},
  year = 	 1992,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-258}
}

@TechReport{UCAM-CL-TR-259,
  author =	 {Abramsky, Samson and Ong, C.-H. Luke},
  title = 	 {{Full abstraction in the Lazy Lambda Calculus}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-259}
}

@TechReport{UCAM-CL-TR-260,
  author =	 {Anderson, Henrik Reif},
  title = 	 {{Local computation of alternating fixed-points}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-260}
}

@TechReport{UCAM-CL-TR-261,
  author =	 {Dodgson, Neil Anthony},
  title = 	 {{Image resampling}},
  year = 	 1992,
  month = 	 aug,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-261.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Image resampling is the process of geometrically
            	  transforming digital images. This report considers
            	  several aspects of the process.
            	  
            	  We begin by decomposing the resampling process into three
            	  simpler sub-processes: reconstruction of a continuous
            	  intensity surface from a discrete image, transformation
            	  of that continuous surface, and sampling of the
            	  transformed surface to produce a new discrete image. We
            	  then consider the sampling process, and the subsidiary
            	  problem of intensity quantisation. Both these are well
            	  understood, and we present a summary of existing work,
            	  laying a foundation for the central body of the report
            	  where the sub-process of reconstruction is studied.
            	  
            	  The work on reconstruction divides into four parts, two
            	  general and two specific:
            	  
            	  1. Piecewise local polynomials: the most studied group of
            	  reconstructors. We examine these, and the criteria used
            	  in their design. One new derivation is of two piecewise
            	  local quadratic reconstructors.
            	  
            	  2. Infinite extent reconstructors: we consider these and
            	  their local approximations, the problem of finite image
            	  size, the resulting edge effects, and the solutions to
            	  these problems. Amongst the reconstructors discussed are
            	  the interpolating cubic B-spline and the interpolating
            	  Bezier cubic. We derive the filter kernels for both of
            	  these, and prove that they are the same. Given this
            	  kernel we demonstrate how the interpolating cubic
            	  B-spline can be extended from a one-dimensional to a
            	  two-dimensional reconstructor, providing a considerable
            	  speed improvement over the existing method of extension.
            	  
            	  3. Fast Fourier transform reconstruction: it has long
            	  been known that the fast Fourier transform (FFT) can be
            	  used to generate an approximation to perfect scaling of a
            	  sample set. Donald Fraser (in 1987) took this result and
            	  generated a hybrid FFT reconstructor which can be used
            	  for general transformations, not just scaling. We modify
            	  Fraser's method to tackle two major problems: its large
            	  time and storage requirements, and the edge effects it
            	  causes in the reconstructed intensity surface.
            	  
            	  4. A priori knowledge reconstruction: first considering
            	  what can be done if we know how the original image was
            	  sampled, and then considering what can be done with one
            	  particular class of image coupled with one particular
            	  type of sampling. In this latter case we find that exact
            	  reconstruction of the image is possible. This is a
            	  surprising result as this class of images cannot be
            	  exactly reconstructed using classical sampling theory.
            	  
            	  The final section of the report draws all of the strands
            	  together to discuss transformations and the resampling
            	  process as a whole. Of particular note here is work on
            	  how the quality of different reconstruction and
            	  resampling methods can be assessed.},
  number = 	 {UCAM-CL-TR-261}
}

@TechReport{UCAM-CL-TR-262,
  author =	 {Benton, Nick and Bierman, Gavin and de Paiva, Valeria},
  title = 	 {{Term assignment for intuitionistic linear logic
         	   (preliminary report)}},
  year = 	 1992,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-262}
}

@TechReport{UCAM-CL-TR-263,
  author =	 {Ong, C.-H. Luke},
  title = 	 {{The Lazy Lambda Calculus: an investigation into the
         	   foundations of functional programming}},
  year = 	 1992,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-263}
}

@TechReport{UCAM-CL-TR-264,
  author =	 {Camilleri, Juanito},
  title = 	 {{CCS with environmental guards}},
  year = 	 1992,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-264}
}

@TechReport{UCAM-CL-TR-265,
  author =	 {Camilleri, Juanito and Melham, Tom},
  title = 	 {{Reasoning with inductively defined relations in the HOL
         	   theorem prover}},
  year = 	 1992,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-265}
}

@TechReport{UCAM-CL-TR-266,
  author =	 {Klein, Carole},
  title = 	 {{Automatic exploitation of OR-parallelism in Prolog}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-266}
}

@TechReport{UCAM-CL-TR-267,
  author =	 {Ernoult, Christine and Mycroft, Alan},
  title = 	 {{Untyped strictness analysis}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-267}
}

@TechReport{UCAM-CL-TR-268,
  author =	 {Jardetzky, Paul W.},
  title = 	 {{Network file server design for continuous media}},
  year = 	 1992,
  month = 	 oct,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-268.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This dissertation concentrates on issues related to the
            	  provision of a network based storage facility for digital
            	  audio and video data. The goal is to demonstrate that a
            	  distributed file service in support of these media may be
            	  built without special purpose hardware. The main
            	  objective is to identify those parameters that affect
            	  file system performance and provide the criteria for
            	  making desirable design decisions.},
  number = 	 {UCAM-CL-TR-268}
}

@TechReport{UCAM-CL-TR-269,
  author =	 {Mycroft, Alan and Norman, Arthur},
  title = 	 {{Optimising compilation}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-269}
}

@TechReport{UCAM-CL-TR-270,
  author =	 {Ma, Chaoying},
  title = 	 {{Designing a universal name service}},
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-270.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Generally speaking, naming in computing systems deals
            	  with the creation of object identifiers at all levels of
            	  system architecture and the mapping among them. Two of
            	  the main purposes of having names in computer systems are
            	  (a) to identify objects; (b) to accomplish sharing.
            	  Without naming no computer system design can be done.
            	  
            	  The rapid development in the technology of personal
            	  workstations and computer communication networks has
            	  placed a great number of demands on designing large
            	  computer naming systems. In this dissertation, issues of
            	  naming in large distributed computing systems are
            	  addressed. Technical aspects as well as system
            	  architecture are examined. A design of a Universal Name
            	  Service (UNS) is proposed and its prototype
            	  implementation is described. Three major issues on
            	  designing a global naming system are studied. Firstly, it
            	  is observed that none of the existing name services
            	  provides enough flexibility in restructuring name spaces,
            	  more research has to be done. Secondly it is observed
            	  that although using stale naming data (hints) at the
            	  application level is acceptable in most cases as long as
            	  it is detectable and recoverable, stronger naming data
            	  integrity should be maintained to provide a better
            	  guarantee of finding objects, especially when a high
            	  degree of availability is required. Finally, configuring
            	  the name service is usually done in an ad hoc manner,
            	  leading to unexpected interruptions or a great deal of
            	  human intervention when the system is reconfigured. It is
            	  necessary to make a systematic study of automatic
            	  configuration and reconfiguration of name services.
            	  
            	  This research is based on a distributed computing model,
            	  in which a number of computers work cooperatively to
            	  provide the service. The contributions include: (a) the
            	  construction of a Globally Unique Directory Identifier
            	  (GUDI) name space. Flexible name space restructuring is
            	  supported by allowing directories to be added to or
            	  removed from the GUDI name space. (b) The definition of a
            	  two class name service infrastructure which exploits the
            	  semantics of naming. It makes the UNS replication control
            	  more robust, reliable as well as highly available. (c)
            	  The identification of two aspects in the name service
            	  configuration: one is concerned with the replication
            	  configuration, and the other is concerned with the server
            	  configuration. It is notable that previous work only
            	  studied these two aspects individually but not in
            	  combination. A distinguishing feature of the UNS is that
            	  both issues are considered at the design stage and novel
            	  methods are used to allow dynamic service configuration
            	  to be done automatically and safely.},
  number = 	 {UCAM-CL-TR-270}
}

@TechReport{UCAM-CL-TR-271,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{Set theory as a computational logic: I. from foundations
         	   to functions}},
  year = 	 1992,
  month = 	 nov,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-271.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {A logic for specification and verification is derived
            	  from the axioms of Zermelo-Fraenkel set theory. The
            	  proofs are performed using the proof assistant Isabelle.
            	  Isabelle is generic, supporting several different logics.
            	  Isabelle has the flexibility to adapt to variants of set
            	  theory. Its higher-order syntax supports the definition
            	  of new binding operators. Unknowns in subgoals can be
            	  instantiated incrementally. The paper describes the
            	  derivation of rules for descriptions, relations and
            	  functions, and discusses interactive proofs of Cantor's
            	  Theorem, the Composition of Homomorphisms challenge, and
            	  Ramsey's Theorem. A generic proof assistant can stand up
            	  against provers dedicated to particular logics.},
  number = 	 {UCAM-CL-TR-271}
}

@TechReport{UCAM-CL-TR-272,
  author =	 {Coen, Martin David},
  title = 	 {{Interactive program derivation}},
  year = 	 1992,
  month = 	 nov,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-272.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {As computer programs are increasingly used in safety
            	  critical applications, program correctness is becoming
            	  more important; as the size and complexity of programs
            	  increases, the traditional approach of testing is
            	  becoming inadequate. Proving the correctness of programs
            	  written in imperative languages is awkward; functional
            	  programming languages, however, offer more hope. Their
            	  logical structure is cleaner, and it is practical to
            	  reason about terminating functional programs in an
            	  internal logic.
            	  
            	  This dissertation describes the development of a logical
            	  theory called TPT for reasoning about the correctness of
            	  terminating functional programs, its implementation using
            	  the theorem prover Isabelle, and its use in proving
            	  formal correctness. The theory draws both from
            	  Martin-L{\"o}f's work in type theory and Manna and
            	  Waldinger's work in program synthesis. It is based on
            	  classical first-order logic, and it contains terms that
            	  represent classes of behaviourally equivalent programs,
            	  types that denote sets of terminating programs and
            	  well-founded orderings. Well-founded induction is used to
            	  reason about general recursion in a natural way and to
            	  separate conditions for termination from those for
            	  correctness.
            	  
            	  The theory is implemented using the generic theorem
            	  prover Isabelle, which allows correctness proofs to be
            	  checked by machine and partially automated using tactics.
            	  In particular, tactics for type checking use the
            	  structure of programs to direct proofs. Type checking
            	  allows both the verification and derivation of programs,
            	  reducing specifications of correctness to sets of
            	  correctness conditions. These conditions can be proved in
            	  typed first-order logic, using well-known techniques of
            	  reasoning by induction and rewriting, and then lifted up
            	  to TPT. Examples of program termination are asserted and
            	  proved, using simple types. Behavioural specifications
            	  are expressed using dependent types, and the correctness
            	  of programs asserted and then proved. As a non-trivial
            	  example, a unification algorithm is specified and proved
            	  correct by machine.
            	  
            	  The work in this dissertation clearly shows how a
            	  classical theory can be used to reason about program
            	  correctness, how general recursion can be reasoned about,
            	  and how programs can direct proofs of correctness.},
  number = 	 {UCAM-CL-TR-272}
}

@TechReport{UCAM-CL-TR-273,
  author =	 {Ferguson, Innes A.},
  title = 	 {{TouringMachines: an architecture for dynamic, rational,
         	   mobile agents}},
  year = 	 1992,
  month = 	 nov,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-273.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {It is becoming widely accepted that neither purely
            	  reactive nor purely deliberative control techniques are
            	  capable of producing the range of behaviours required of
            	  intelligent computational or robotic agents in dynamic,
            	  unpredictable, multi-agent worlds. We present a new
            	  architecture for controlling autonomous, mobile agents --
            	  building on previous work addressing reactive and
            	  deliberative control methods. The proposed multi-layered
            	  control architecture allows a resource-bounded,
            	  goal-directed agent to react promptly to unexpected
            	  changes in its environment; at the same time it enables
            	  the agent to reason predictively about potential
            	  conflicts by constructing and projecting causal models or
            	  theories which hypothesise other agents' goals and
            	  intentions.
            	  
            	  The line of research adopted is very much a pragmatic
            	  one. A single, common architecture has been implemented
            	  which, being extensively parametrized, allows an
            	  experimenter to study functionally- and
            	  behaviourally-diverse agent configurations. A principal
            	  aim of this research is to understand the role different
            	  functional capabilities play in constraining an agent's
            	  behaviour under varying environmental conditions. To this
            	  end, we have constructed an experimental testbed
            	  comprising a simulated multi-agent world in which a
            	  variety of agent configurations and behaviours have been
            	  investigated. Experience with the new control
            	  architecture is described.},
  number = 	 {UCAM-CL-TR-273}
}

@TechReport{UCAM-CL-TR-274,
  author =	 {Curzon, Paul},
  title = 	 {{Of what use is a verified compiler specification?}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-274}
}

@TechReport{UCAM-CL-TR-275,
  author =	 {Pell, Barney},
  title = 	 {{Exploratory learning in the game of GO}},
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-275.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This paper considers the importance of exploration to
            	  game-playing programs which learn by playing against
            	  opponents. The central question is whether a learning
            	  program should play the move which offers the best chance
            	  of winning the present game, or if it should play the
            	  move which has the best chance of providing useful
            	  information for future games. An approach to addressing
            	  this question is developed using probability theory, and
            	  then implemented in two different learning methods.
            	  Initial experiments in the game of Go suggest that a
            	  program which takes exploration into account can learn
            	  better against a knowledgeable opponent than a program
            	  which does not.},
  number = 	 {UCAM-CL-TR-275}
}

@TechReport{UCAM-CL-TR-276,
  author =	 {Pell, Barney},
  title = 	 {{METAGAME: a new challenge for games and learning}},
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-276.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {In most current approaches to Computer Game-Playing,
            	  including those employing some form of machine learning,
            	  the game analysis mainly is performed by humans. Thus, we
            	  are sidestepping largely the interesting (and difficult)
            	  questions. Human analysis also makes it difficult to
            	  evaluate the generality and applicability of different
            	  approaches.
            	  
            	  To address these problems, we introduce a new challenge:
            	  Metagame. The idea is to write programs which take as
            	  input the rules of a set of new games within a
            	  pre-specified class, generated by a program which is
            	  publicly available. The programs compete against each
            	  other in many matches on each new game, and they can then
            	  be evaluated based on their overall performance and
            	  improvement through experience.
            	  
            	  This paper discusses the goals, research areas, and
            	  general concerns for the idea of Metagame.},
  number = 	 {UCAM-CL-TR-276}
}

@TechReport{UCAM-CL-TR-277,
  author =	 {Pell, Barney},
  title = 	 {{METAGAME in symmetric chess-like games}},
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-277.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {I have implemented a game generator that generates games
            	  from a wide but still restricted class. This class is
            	  general enough to include most aspects of many standard
            	  games, including Chess, Shogi, Chinese Chess, Checkers,
            	  Draughts, and many variants of Fairy Chess. The
            	  generator, implemented in Prolog is transparent and
            	  publicly available, and generates games using probability
            	  distributions for parameters such as piece complexity,
            	  types of movement, board size, and locality.
            	  
            	  The generator is illustrated by means of a new game it
            	  produced, which is then subjected to a simple strategic
            	  analysis. This form of analysis suggests that programs to
            	  play Metagame well will either learn or apply very
            	  general game-playing principles. But because the class is
            	  still restricted, it may be possible to develop a naive
            	  but fast program which can outplay more sophisticated
            	  opponents. Performance in a tournament between programs
            	  is the deciding criterion.},
  number = 	 {UCAM-CL-TR-277}
}

@TechReport{UCAM-CL-TR-278,
  author =	 {Nesi, Monica},
  title = 	 {{A formalization of the process algebra CCS in high order
         	   logic}},
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-278.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This paper describes a mechanization in higher order
            	  logic of the theory for a subset of Milner's CCS. The aim
            	  is to build a sound and effective tool to support
            	  verification and reasoning about process algebra
            	  specifications. To achieve this goal, the formal theory
            	  for pure CCS (no value passing) is defined in the
            	  interactive theorem prover HOL, and a set of proof tools,
            	  based on the algebraic presentation of CCS, is provided.},
  number = 	 {UCAM-CL-TR-278}
}

@TechReport{UCAM-CL-TR-279,
  author =	 {Carre{\~n}o, Victor A.},
  title = 	 {{The transition assertions specification method}},
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-279}
}

@TechReport{UCAM-CL-TR-280,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{Introduction to Isabelle}},
  year = 	 1993,
  month = 	 jan,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-280.dvi.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Isabelle is a generic theorem prover, supporting formal
            	  proof in a variety of logics. Through a variety of
            	  examples, this paper explains the basic theory
            	  demonstrates the most important commands. It serves as
            	  the introduction to other Isabelle documentation.},
  number = 	 {UCAM-CL-TR-280}
}

@TechReport{UCAM-CL-TR-281,
  author =	 {Mullender, Sape J. and Leslie, Ian M. and McAuley, Derek},
  title = 	 {{Pegasus project description}},
  year = 	 1992,
  month = 	 sep,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-281}
}

@TechReport{UCAM-CL-TR-282,
  author =	 {Leslie, Ian M. and McAuley, Derek and Mullender, Sape J.},
  title = 	 {{Pegasus -- Operating system support for distributed
         	   multimedia systems}},
  year = 	 1992,
  month = 	 dec,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-282}
}

@TechReport{UCAM-CL-TR-283,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{The Isabelle reference manual}},
  year = 	 1993,
  month = 	 feb,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-283.dvi.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This manual is a comprehensive description of Isabelle,
            	  including all commands, functions and packages. It is
            	  intended for reference rather than for reading through,
            	  and is certainly not a tutorial. The manual assumes
            	  familiarity with the basic concepts explained in
            	  Introduction to Isabelle. Functions are organized by
            	  their purpose, by their operands (subgoals, tactics,
            	  theorems), and by their usefulness. In each section,
            	  basic functions appear first, then advanced functions,
            	  and finally esoteric functions.},
  number = 	 {UCAM-CL-TR-283}
}

@TechReport{UCAM-CL-TR-284,
  author =	 {Grover, Claire and Carroll, John and Briscoe, Ted},
  title = 	 {{The Alvey Natural Language Tools grammar (4th Release)}},
  year = 	 1993,
  month = 	 jan,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-284}
}

@TechReport{UCAM-CL-TR-285,
  author =	 {Gordon, Andrew Donald},
  title = 	 {{Functional programming and input/output}},
  year = 	 1993,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-285}
}

@TechReport{UCAM-CL-TR-286,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{Isabelle's object-logics}},
  year = 	 1993,
  month = 	 feb,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-286.dvi.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Several logics come with Isabelle. Many of them are
            	  sufficiently developed to serve as comfortable reasoning
            	  environments. They are also good starting points for
            	  defining new logics. Each logic is distributed with
            	  sample proofs, some of which are presented in the paper.
            	  The logics described include first-order logic,
            	  Zermelo-Fraenkel set theory, higher-order logic,
            	  constructive type theory, and the classical sequent
            	  calculus LK. A final chapter explains the fine points of
            	  defining logics in Isabelle.},
  number = 	 {UCAM-CL-TR-286}
}

@TechReport{UCAM-CL-TR-287,
  author =	 {Gordon, Andrew D.},
  title = 	 {{A mechanised definition of Silage in HOL}},
  year = 	 1993,
  month = 	 feb,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-287.dvi.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {If formal methods of hardware verification are to have
            	  any impact on the practices of working engineers,
            	  connections must be made between the languages used in
            	  practice to design circuits, and those used for research
            	  into hardware verification. Silage is a simple dataflow
            	  language marketed for specifying digital signal
            	  processing circuits. Higher Order Logic (HOL) is
            	  extensively used for research into hardware verification.
            	  This paper presents a formal definition of a substantial
            	  subset of Silage, by mapping Silage declarations into HOL
            	  predicates. The definition has been mechanised in the HOL
            	  theorem prover to support the transformational design of
            	  Silage circuits as theorem proving in HOL.},
  number = 	 {UCAM-CL-TR-287}
}

@TechReport{UCAM-CL-TR-288,
  author =	 {Gore, Rajeev},
  title = 	 {{Cut-free sequent and tableau systems for propositional
         	   Diodorean modal logics}},
  year = 	 1993,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-288}
}

@TechReport{UCAM-CL-TR-289,
  author =	 {Elworthy, David Alan Howard},
  title = 	 {{The semantics of noun phrase anaphora}},
  year = 	 1993,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-289}
}

@TechReport{UCAM-CL-TR-290,
  author =	 {Sp{\"a}rck Jones, Karen},
  title = 	 {{Discourse modelling for automatic summarising}},
  year = 	 1993,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-290}
}

@TechReport{UCAM-CL-TR-291,
  author =	 {Galliers, J.R. and Sp{\"a}rck Jones, K.},
  title = 	 {{Evaluating natural language processing systems}},
  year = 	 1993,
  month = 	 feb,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-291.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This report presents a detailed analysis and review of
            	  NLP evaluation, in principle and in practice. Part 1
            	  examines evaluation concepts and establishes a framework
            	  for NLP system evaluation. This makes use of experience
            	  in the related area of information retrieval and the
            	  analysis also refers to evaluation in speech processing.
            	  Part 2 surveys significant evaluation work done so far,
            	  for instance in machine translation, and discusses the
            	  particular problems of generic system evaluation. The
            	  conclusion is that evaluation strategies and techniques
            	  for NLP need much more development, in particular to take
            	  proper account of the influence of system tasks and
            	  settings. Part 3 develops a general approach to NLP
            	  evaluation, aimed at methodologically-sound strategies
            	  for test and evaluation motivated by comprehensive
            	  performance factor identification. The analysis
            	  throughout the report is supported by extensive
            	  illustrative examples.},
  number = 	 {UCAM-CL-TR-291}
}

@TechReport{UCAM-CL-TR-292,
  author =	 {Sreenan, Cormac John},
  title = 	 {{Synchronisation services for digital continuous media}},
  year = 	 1993,
  month = 	 mar,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-292.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The development of broadband ATM networking makes it
            	  attractive to use computer communication networks for the
            	  transport of digital audio and motion video. Coupled with
            	  advances in workstation technology, this creates the
            	  opportunity to integrate these continuous information
            	  media within a distributed computing system. Continuous
            	  media have an inherent temporal dimension, resulting in a
            	  set of synchronisation requirements which have real-time
            	  constraints. This dissertation identifies the role and
            	  position of synchronisation, in terms of the support
            	  which is necessary in an integrated distributed system.
            	  This work is supported by a set of experiments which were
            	  performed in an ATM inter-network using multi-media
            	  workstations, each equipped with an Olivetti Pandora Box.},
  number = 	 {UCAM-CL-TR-292}
}

@TechReport{UCAM-CL-TR-293,
  author =	 {Bacon, Jean and Moody, Ken},
  title = 	 {{Objects and transactions for modelling distributed
         	   applications: concurrency control and commitment}},
  year = 	 1993,
  month = 	 apr,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-293}
}

@TechReport{UCAM-CL-TR-294,
  author =	 {Moody, Ken and Bacon, Jean and Adly, Noha and Afshar,
          	  Mohamad and Bates, John and Feng, Huang and Hayton, Richard
          	  and Lo, Sai Lai and Schwiderski, Scarlet and Sultana,
          	  Robert and Wu, Zhixue},
  title = 	 {{OPERA : Storage, programming and display of multimedia
         	   objects}},
  year = 	 1993,
  month = 	 apr,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-294}
}

@TechReport{UCAM-CL-TR-295,
  author =	 {Bacon, Jean and Bates, John and Lo, Sai Lai and Moody, Ken},
  title = 	 {{OPERA : Storage and presentation support for multimedia
         	   applications in a distributed, ATM network environment}},
  year = 	 1993,
  month = 	 apr,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-295}
}

@TechReport{UCAM-CL-TR-296,
  author =	 {Wu, Z. and Moody, K. and Bacon, J.},
  title = 	 {{A persistent programming language for multimedia databases
         	   in the OPERA project}},
  year = 	 1993,
  month = 	 apr,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-296}
}

@TechReport{UCAM-CL-TR-297,
  author =	 {Ritter, Eike},
  title = 	 {{Categorical abstract machines for higher-order lambda
         	   calculi}},
  year = 	 1993,
  month = 	 apr,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-297}
}

@TechReport{UCAM-CL-TR-298,
  author =	 {Doar, John Matthew Simon},
  title = 	 {{Multicast in the asynchronous transfer mode environment}},
  year = 	 1993,
  month = 	 apr,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-298.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {In future multimedia communication networks, the ability
            	  to multicast information will be useful for many new and
            	  existing services. This dissertation considers the design
            	  of multicast switches for Asynchronous Transfer Mode
            	  (ATM) networks and proposes one design based upon a
            	  slotted ring. Analysis and simulation studies of this
            	  design are presented and details of its implementation
            	  for an experimental ATM network (Project Fairisle) are
            	  described, together with the modifications to the
            	  existing multi-service protocol architecture necessary to
            	  provide multicast connections. Finally, a short study of
            	  the problem of multicast routing is presented, together
            	  with some simulations of the long-term effect upon the
            	  routing efficiency of modifying the number of
            	  destinations within a multicast group.},
  number = 	 {UCAM-CL-TR-298}
}

@TechReport{UCAM-CL-TR-299,
  author =	 {Gamback, Bjorn and Rayner, Manny and Pell, Barney},
  title = 	 {{Pragmatic reasoning in bridge}},
  year = 	 1993,
  month = 	 apr,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-299.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {In this paper we argue that bidding in the game of
            	  Contract Bridge can profitably be regarded as a
            	  micro-world suitable for experimenting with pragmatics.
            	  We sketch an analysis in which a ``bidding system'' is
            	  treated as the semantics of an artificial language, and
            	  show how this ``language'', despite its apparent
            	  simplicity, is capable of supporting a wide variety of
            	  common speech acts parallel to those in natural
            	  languages; we also argue that the reason for the
            	  relatively unsuccessful nature of previous attempts to
            	  write strong Bridge playing programs has been their
            	  failure to address the need to reason explicitly about
            	  knowledge, pragmatics, probabilities and plans. We give
            	  an overview of Pragma, a system currently under
            	  development, which embodies these ideas in concrete form,
            	  using a combination of rule-based inference, stochastic
            	  simulation, and ``neural-net'' learning. Examples are
            	  given illustrating the functionality of the system in its
            	  current form.},
  number = 	 {UCAM-CL-TR-299}
}

@TechReport{UCAM-CL-TR-300,
  author =	 {Wong, Wai},
  title = 	 {{Formal verification of VIPER's ALU}},
  year = 	 1993,
  month = 	 apr,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-300}
}

@TechReport{UCAM-CL-TR-301,
  author =	 {Wu, Zhixue and Moody, Ken and Bacon, Jean},
  title = 	 {{The dual-level validation concurrency control method}},
  year = 	 1993,
  month = 	 jun,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-301}
}

@TechReport{UCAM-CL-TR-302,
  author =	 {Pell, Barney},
  title = 	 {{Logic programming for general game-playing}},
  year = 	 1993,
  month = 	 jun,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-302.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Meta-Game Playing is a new approach to games in
            	  Artificial Intelligence, where we construct programs to
            	  play new games in a well-defined class, which are output
            	  by an automatic game generator. As the specific games to
            	  be played are not known in advance, a degree of human
            	  bias is eliminated, and playing programs are required to
            	  perform any game-specific optimisations without human
            	  assistance.
            	  
            	  The attempt to construct a general game-playing program
            	  is made difficult by the opposing goals of generality and
            	  efficiency. This paper shows how application of standard
            	  techniques in logic-programming (abstract interpretation
            	  and partial evaluation) makes it possible to achieve both
            	  of these goals. Using these techniques, we can represent
            	  the semantics of a large class of games in a general and
            	  declarative way, but then have the program transform this
            	  representation into a more efficient version once it is
            	  presented with the rules of a new game. This process can
            	  be viewed as moving some of the responsibility for game
            	  analysis (that concerned with efficiency) from the
            	  researcher to the program itself.},
  number = 	 {UCAM-CL-TR-302}
}

@TechReport{UCAM-CL-TR-303,
  author =	 {Kennedy, Andrew},
  title = 	 {{Drawing trees --- a case study in functional programming}},
  year = 	 1993,
  month = 	 jun,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-303}
}

@TechReport{UCAM-CL-TR-304,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{Co-induction and co-recursion in higher-order logic}},
  year = 	 1993,
  month = 	 jul,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-304.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {A theory of recursive and corecursive definitions has
            	  been developed in higher-order logic (HOL) and mechanised
            	  using Isabelle. Least fixedpoints express inductive data
            	  types such as strict lists; greatest fixedpoints express
            	  co-inductive data types, such as lazy lists. Well-founded
            	  recursion expresses recursive functions over inductive
            	  data types; co-recursion expresses functions that yield
            	  elements of co-inductive data types. The theory rests on
            	  a traditional formalization of infinite trees. The theory
            	  is intended for use in specification and verification. It
            	  supports reasoning about a wide range of computable
            	  functions, but it does not formalize their operational
            	  semantics and can express noncomputable functions also.
            	  The theory is demonstrated using lists and lazy lists as
            	  examples. The emphasis is on using co-recursion to define
            	  lazy list functions, and on using co-induction to reason
            	  about them.},
  number = 	 {UCAM-CL-TR-304}
}

@TechReport{UCAM-CL-TR-305,
  author =	 {Benton, P.N.},
  title = 	 {{Strong normalisation for the linear term calculus}},
  year = 	 1993,
  month = 	 jul,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-305}
}

@TechReport{UCAM-CL-TR-306,
  author =	 {Wong, Wai},
  title = 	 {{Recording HOL proofs}},
  year = 	 1993,
  month = 	 jul,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-306}
}

@TechReport{UCAM-CL-TR-307,
  author =	 {Lewis, David D. and Sp{\"a}rck Jones, Karen},
  title = 	 {{Natural language processing for information retrieval}},
  year = 	 1993,
  month = 	 jul,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-307.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The paper summarizes the essential properties of
            	  document retrieval and reviews both conventional practice
            	  and research findings, the latter suggesting that simple
            	  statistical techniques can be effective. It then
            	  considers the new opportunities and challenges presented
            	  by the ability to search full text directly (rather than
            	  e.g. titles and abstracts), and suggests appropriate
            	  approaches to doing this, with a focus on the role of
            	  natural language processing. The paper also comments on
            	  possible connections with data and knowledge retrieval,
            	  and concludes by emphasizing the importance of rigorous
            	  performance testing.},
  number = 	 {UCAM-CL-TR-307}
}

@TechReport{UCAM-CL-TR-308,
  author =	 {Frost, Jacob},
  title = 	 {{A case study of co-induction in Isabelle HOL}},
  year = 	 1993,
  month = 	 aug,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-308.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The consistency of the dynamic and static semantics for
            	  a small functional programming language was informally
            	  proved by R. Milner and M. Tofte. The notions of
            	  co-inductive definitions and the associated principle of
            	  co-induction played a pivotal role in the proof. With
            	  emphasis on co-induction, the work presented here deals
            	  with the formalisation of this result in the higher-order
            	  logic of the generic theorem prover Isabelle.},
  number = 	 {UCAM-CL-TR-308}
}

@TechReport{UCAM-CL-TR-309,
  author =	 {Benton, Peter Nicholas},
  title = 	 {{Strictness analysis of lazy functional programs}},
  year = 	 1993,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-309}
}

@TechReport{UCAM-CL-TR-310,
  author =	 {Adly, Noha},
  title = 	 {{HARP: a hierarchical asynchronous replication protocol for
         	   massively replicated systems}},
  year = 	 1993,
  month = 	 aug,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-310.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-310}
}

@TechReport{UCAM-CL-TR-311,
  author =	 {Curzon, Paul},
  title = 	 {{A verified Vista implementation}},
  year = 	 1993,
  month = 	 sep,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-311}
}

@TechReport{UCAM-CL-TR-312,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{Set theory for verification: II : Induction and recursion}},
  year = 	 1993,
  month = 	 sep,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-312.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {A theory of recursive definitions has been mechanized in
            	  Isabelle's Zermelo-Fraenkel (ZF) set theory. The
            	  objective is to support the formalization of particular
            	  recursive definitions for use in verification, semantics
            	  proofs and other computational reasoning.
            	  
            	  Inductively defined sets are expressed as least
            	  fixedpoints, applying the Knaster-Tarski Theorem over a
            	  suitable set. Recursive functions are defined by
            	  well-founded recursion and its derivatives, such as
            	  transfinite recursion. Recursive data structures are
            	  expressed by applying the Knaster-Tarski Theorem to a set
            	  that is closed under Cartesian product and disjoint sum.
            	  
            	  Worked examples include the transitive closure of a
            	  relation, lists, variable-branching trees and mutually
            	  recursive trees and forests. The Schr{\"o}der-Bernstein
            	  Theorem and the soundness of propositional logic are
            	  proved in Isabelle sessions.},
  number = 	 {UCAM-CL-TR-312}
}

@TechReport{UCAM-CL-TR-313,
  author =	 {Bertot, Yves and Kahn, Gilles and Th{\'e}ry, Laurent},
  title = 	 {{Proof by pointing}},
  year = 	 1993,
  month = 	 oct,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-313}
}

@TechReport{UCAM-CL-TR-314,
  author =	 {Carroll, John Andrew},
  title = 	 {{Practical unification-based parsing of natural language}},
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-314.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The thesis describes novel techniques and algorithms for
            	  the practical parsing of realistic Natural Language (NL)
            	  texts with a wide-coverage unification-based grammar of
            	  English. The thesis tackles two of the major problems in
            	  this area: firstly, the fact that parsing realistic
            	  inputs with such grammars can be computationally very
            	  expensive, and secondly, the observation that many
            	  analyses are often assigned to an input, only one of
            	  which usually forms the basis of the correct
            	  interpretation.
            	  
            	  The thesis starts by presenting a new unification
            	  algorithm, justifies why it is well-suited to practical
            	  NL parsing, and describes a bottom-up active chart parser
            	  which employs this unification algorithm together with
            	  several other novel processing and optimisation
            	  techniques. Empirical results demonstrate that an
            	  implementation of this parser has significantly better
            	  practical performance than a comparable, state-of-the-art
            	  unification-based parser. Next, techniques for computing
            	  an LR table for a large unification grammar are
            	  described, a context free non-deterministic LR parsing
            	  algorithm is presented which has better time complexity
            	  than any previously reported using the same approach, and
            	  a unification-based version is derived. In experiments,
            	  the performance of an implementation of the latter is
            	  shown to exceed both the chart parser and also that of
            	  another efficient LR-like algorithm recently proposed.
            	  
            	  Building on these methods, a system for parsing text
            	  taken from a given corpus is described which uses
            	  probabilistic techniques to identify the most plausible
            	  syntactic analyses for an input from the often large
            	  number licensed by the grammar. New techniques
            	  implemented include an incremental approach to
            	  semi-supervised training, a context-sensitive method of
            	  scoring sub-analyses, the accurate manipulation of
            	  probabilities during parsing, and the identification of
            	  the highest ranked analyses without exhaustive search.
            	  The system attains a similar success rate to approaches
            	  based on context-free grammar, but produces analyses
            	  which are more suitable for semantic processing.
            	  
            	  The thesis includes detailed analyses of the worst-case
            	  space and time complexities of all the main algorithms
            	  described, and discusses the practical impact of the
            	  theoretical complexity results.},
  number = 	 {UCAM-CL-TR-314}
}

@TechReport{UCAM-CL-TR-315,
  author =	 {Pell, Barney Darryl},
  title = 	 {{Strategy generation and evaluation for meta-game playing}},
  year = 	 1993,
  month = 	 nov,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-315.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Meta-Game Playing (METAGAME) is a new paradigm for
            	  research in game-playing in which we design programs to
            	  take in the rules of unknown games and play those games
            	  without human assistance. Strong performance in this new
            	  paradigm is evidence that the program, instead of its
            	  human designer, has performed the analysis of each
            	  specific game.
            	  
            	  SCL-METAGAME is a concrete METAGAME research problem
            	  based around the class of symmetric chess-like games. The
            	  class includes the games of chess, checkers, noughts and
            	  crosses, Chinese-chess, and Shogi. An implemented game
            	  generator produces new games in this class, some of which
            	  are objects of interest in their own right.
            	  
            	  METAGAMER is a program that plays SCL-METAGAME. The
            	  program takes as input the rules of a specific game and
            	  analyses those rules to construct for that game an
            	  efficient representation and an evaluation function, both
            	  for use with a generic search engine. The strategic
            	  analysis performed by the program relates a set of
            	  general knowledge sources to the details of the
            	  particular game. Among other properties, this analysis
            	  determines the relative value of the different pieces in
            	  a given game. Although METAGAMER does not learn from
            	  experience, the values resulting from its analysis are
            	  qualitatively similar to values used by experts on known
            	  games, and are sufficient to produce competitive
            	  performance the first time the program actually plays
            	  each game it is given. This appears to be the first
            	  program to have derived useful piece values directly from
            	  analysis of the rules of different games.
            	  
            	  Experiments show that the knowledge implemented in
            	  METAGAMER is useful on games unknown to its programmer in
            	  advance of the competition and make it seem likely that
            	  future programs which incorporate learning and more
            	  sophisticated active-analysis techniques will have a
            	  demonstrable competitive advantage on this new problem.
            	  When playing the known games of chess and checkers
            	  against humans and specialised programs, METAGAMER has
            	  derived from more general principles some strategies
            	  which are familiar to players of those games and which
            	  are hard-wired in many game-specific programs.},
  number = 	 {UCAM-CL-TR-315}
}

@TechReport{UCAM-CL-TR-316,
  author =	 {Copestake, Ann},
  title = 	 {{The Compleat LKB}},
  year = 	 1993,
  month = 	 aug,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-316.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-316}
}

@TechReport{UCAM-CL-TR-317,
  author =	 {Van Tassel, John Peter},
  title = 	 {{Femto-VHDL: the semantics of a subset of VHDL and its
         	   embedding in the HOL proof assistant}},
  year = 	 1993,
  month = 	 nov,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-317}
}

@TechReport{UCAM-CL-TR-318,
  author =	 {Grundy, Jim},
  title = 	 {{A method of program refinement}},
  year = 	 1993,
  month = 	 nov,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-318.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {A method of specifying the desired behaviour of a
            	  computer program, and of refining such specifications
            	  into imperative programs is proposed. The refinement
            	  method has been designed with the intention of being
            	  amenable to tool support, and of being applicable to
            	  real-world refinement problems.
            	  
            	  Part of the refinement method proposed involves the use
            	  of a style of transformational reasoning called `window
            	  inference'. Window inference is particularly powerful
            	  because it allows the information inherent in the context
            	  of a subexpression to be used in its transformation. If
            	  the notion of transformational reasoning is generalised
            	  to include transformations that preserve relationships
            	  weaker than equality, then program refinement can be
            	  regarded as a special case of transformational reasoning.
            	  A generalisation of window inference is described that
            	  allows non-equivalence preserving transformations. Window
            	  inference was originally proposed independently from, and
            	  as an alternative to, traditional styles of reasoning. A
            	  correspondence between the generalised version of window
            	  inference and natural deduction is described. This
            	  correspondence forms the basis of a window inference tool
            	  that has been built on top of the HOL theorem proving
            	  system.
            	  
            	  This dissertation adopts a uniform treatment of
            	  specifications and programs as predicates. A survey of
            	  the existing approaches to the treatment of programs as
            	  predicates is presented. A new approach is then developed
            	  based on using predicates of a three-valued logic. This
            	  new approach can distinguish more easily between
            	  specifications of terminating and nonterminating
            	  behaviour than can the existing approaches.
            	  
            	  A method of program refinement is then described by
            	  combining the unified treatment of specifications and
            	  programs as three-valued predicates with the window
            	  inference style of transformational reasoning. The result
            	  is a simple method of refinement that is well suited to
            	  the provision of tool support.
            	  
            	  The method of refinement includes a technique for
            	  developing recursive programs. The proof of such
            	  developments is usually complicated because little can be
            	  assumed about the form and termination properties of a
            	  partially developed program. These difficulties are
            	  side-stepped by using a simplified meaning for recursion
            	  that compels the development of terminating programs.
            	  Once the development of a program is complete, the
            	  simplified meaning for recursion is refined into the true
            	  meaning.
            	  
            	  The dissertation concludes with a case study which
            	  presents the specification and development of a simple
            	  line-editor. The case study demonstrates the
            	  applicability of the refinement method to real-world
            	  problems. The line editor is a nontrivial example that
            	  contains features characteristic of large developments,
            	  including complex data structures and the use of data
            	  abstraction. Examination of the case study shows that
            	  window inference offers a convenient way of structuring
            	  large developments.},
  number = 	 {UCAM-CL-TR-318}
}

@TechReport{UCAM-CL-TR-319,
  author =	 {Hayter, Mark David},
  title = 	 {{A workstation architecture to support multimedia}},
  year = 	 1993,
  month = 	 nov,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-319.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The advent of high speed networks in the wide and local
            	  area enables multimedia traffic to be easily carried
            	  between workstation class machines. The dissertation
            	  considers an architecture for a workstation to support
            	  such traffic effectively. In addition to presenting the
            	  information to a human user the architecture allows
            	  processing to be done on continuous media streams.
            	  
            	  The proposed workstation architecture, known as the Desk
            	  Area Network (DAN), extends ideas from Asynchronous
            	  Transfer Mode (ATM) networks into the end-system. All
            	  processors and devices are connected to an ATM
            	  interconnect. The architecture is shown to be capable of
            	  supporting both multimedia data streams and more
            	  traditional CPU cache line traffic. The advocated
            	  extension of the CPU cache which allows caching of
            	  multimedia data streams is shown to provide a natural
            	  programming abstraction and a mechanism for synchronising
            	  the processor with the stream.
            	  
            	  A prototype DAN workstation has been built. Experiments
            	  have been done to demonstrate the features of the
            	  architecture. In particular the use of the DAN as a
            	  processor-to-memory interconnect is closely studied to
            	  show the practicality of using ATM for cache line traffic
            	  in a real machine. Simple demonstrations of the stream
            	  cache ideas are used to show its utility in future
            	  applications.},
  number = 	 {UCAM-CL-TR-319}
}

@TechReport{UCAM-CL-TR-320,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{A fixedpoint approach to implementing (co)inductive
         	   definitions (updated version)}},
  year = 	 1995,
  month = 	 jul,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-320.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Several theorem provers provide commands for formalizing
            	  recursive datatypes or inductively defined sets. This
            	  paper presents a new approach, based on fixedpoint
            	  definitions. It is unusually general: it admits all
            	  monotone inductive definitions. It is conceptually
            	  simple, which has allowed the easy implementation of
            	  mutual recursion and other conveniences. It also handles
            	  coinductive definitions: simply replace the least
            	  fixedpoint by a greatest fixedpoint. This represents the
            	  first automated support for coinductive definitions.
            	  
            	  The method has been implemented in Isabelle's
            	  formalization of ZF set theory. It should be applicable
            	  to any logic in which the Knaster-Tarski Theorem can be
            	  proved. The paper briefly describes a method of
            	  formalizing non-well-founded data structures in standard
            	  ZF set theory.
            	  
            	  Examples include lists of n elements, the accessible part
            	  of a relation and the set of primitive recursive
            	  functions. One example of a coinductive definition is
            	  bisimulations for lazy lists. Recursive datatypes are
            	  examined in detail, as well as one example of a
            	  ``codatatype'': lazy lists. The appendices are simple
            	  user's manuals for this Isabelle/ZF package.},
  number = 	 {UCAM-CL-TR-320}
}

@TechReport{UCAM-CL-TR-321,
  author =	 {Pitts, Andrew M.},
  title = 	 {{Relational properties of domains}},
  year = 	 1993,
  month = 	 dec,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-321.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {New tools are presented for reasoning about properties
            	  of recursively defined domains. We work within a general,
            	  category-theoretic framework for various notions of
            	  `relation' on domains and for actions of domain
            	  constructors on relations. Freyd's analysis of recursive
            	  types in terms of a property of mixed initiality/finality
            	  is transferred to a corresponding property of invariant
            	  relations. The existence of invariant relations is proved
            	  under completeness assumptions about the notion of
            	  relation. We show how this leads to simpler proofs of the
            	  computational adequacy of denotational semantics for
            	  functional programming languages with user-declared
            	  datatypes. We show how the initiality/finality property
            	  of invariant relations can be specialized to yield an
            	  induction principle for admissible subsets of recursively
            	  defined domains, generalizing the principle of structural
            	  induction for inductively defined sets. We also show how
            	  the initiality/finality property gives rise to the
            	  co-induction principle studied by the author (in
            	  UCAM-CL-TR-252), by which equalities between elements of
            	  recursively defined domains may be proved via an
            	  appropriate notion of `bisimulation'.},
  number = 	 {UCAM-CL-TR-321}
}

@TechReport{UCAM-CL-TR-322,
  author =	 {Li, Guangxing},
  title = 	 {{Supporting distributed realtime computing}},
  year = 	 1993,
  month = 	 dec,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-322}
}

@TechReport{UCAM-CL-TR-323,
  author =	 {von Wright, J.},
  title = 	 {{Representing higher-order logic proofs in HOL}},
  year = 	 1994,
  month = 	 jan,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-323}
}

@TechReport{UCAM-CL-TR-324,
  author =	 {von Wright, J.},
  title = 	 {{Verifying modular programs in HOL}},
  year = 	 1994,
  month = 	 jan,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-324}
}

@TechReport{UCAM-CL-TR-325,
  author =	 {Crouch, Richard},
  title = 	 {{The temporal properties of English conditionals and modals}},
  year = 	 1994,
  month = 	 jan,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-325.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This thesis deals with the patterns of temporal
            	  reference exhibited by conditional and modal sentences in
            	  English, and specifically with the way that past and
            	  present tenses can undergo deictic shift in these
            	  contexts. This shifting behaviour has consequences both
            	  for the semantics of tense and for the semantics of
            	  conditionals and modality.
            	  
            	  Asymmetries in the behaviour of the past and present
            	  tenses under deictic shift are explained by positing a
            	  primary and secondary deictic centre for tenses. The two
            	  deictic centres, the assertion time and the verification
            	  time, are given independent motivation through an
            	  information based view of tense. This holds that the
            	  tense system not only serves to describe the way that the
            	  world changes over time, but also the way that
            	  information about the world changes. Information change
            	  takes place in two stages. First, it is asserted that
            	  some fact holds. And then, either at the same time or
            	  later, it is verified that is assertion is correct.
            	  
            	  Typically, assertion and verification occur
            	  simultaneously, and most sentences convey verified
            	  information. Modals and conditionals allow delayed
            	  assertion and verification. ``If A, then B'' means
            	  roughly: suppose you were now to assert A; if and when A
            	  is verified, you will be in a position to assert B, and
            	  in due course this assertion will also be verified. Since
            	  A and B will both be tensed clauses, the shifting of the
            	  primary and secondary deictic centres leads to shifted
            	  interpretations of the two clauses.
            	  
            	  The thesis presents a range of temporal properties of
            	  indicative and subjunctive conditionals that have not
            	  previously been discussed, and shows how they can be
            	  explained. A logic is presented for indicative
            	  conditionals, based around an extension of intuitionistic
            	  logic to allow for both verified and unverified
            	  assertions. This logic naturally gives rise to three
            	  forms of epistemic modality, corresponding to ``must'',
            	  ``may'' and ``will''.},
  number = 	 {UCAM-CL-TR-325}
}

@TechReport{UCAM-CL-TR-326,
  author =	 {Lo, Sai-Lai},
  title = 	 {{A modular and extensible network storage architecture}},
  year = 	 1994,
  month = 	 jan,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-326.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Most contemporary distributed file systems are not
            	  designed to be extensible. This work asserts that the
            	  lack of extensibility is a problem because:
            	  
            	  -- New data types, such as continuous-medium data and
            	  structured data, are significantly different from
            	  conventional unstructured data, such as text and binary,
            	  that contemporary distributed file systems are built to
            	  support.
            	  
            	  -- Value-adding clients can provide functional
            	  enhancements, such as convenient and reliable persistent
            	  programming and automatic and transparent file indexing,
            	  but cannot be integrated smoothly with contemporary
            	  distributed file systems.
            	  
            	  -- New media technologies, such as the optical jukebox
            	  and RAID disk, can extend the scale and performance of a
            	  storage service but contemporary distributed file systems
            	  do not have a clear framework to incorporate these new
            	  technologies and to provide the necessary user level
            	  transparency.
            	  
            	  Motivated by these observations, the new network storage
            	  architecture (MSSA) presented in this dissertation, is
            	  designed to be extensible. Design modularity is taken as
            	  the key to achieve service extensibility. This
            	  dissertation examines a number of issues related to the
            	  design of the architecture. New ideas, such as a flexible
            	  access control mechanism based on temporary capabilities,
            	  a low level storage substrate that uses non-volatile
            	  memory to provide atomic update semantics at high
            	  performance, a concept of sessions to differentiate
            	  performance requirements of different data types, are
            	  introduced. Prototype implementations of the key
            	  components are evaluated.},
  number = 	 {UCAM-CL-TR-326}
}

@TechReport{UCAM-CL-TR-327,
  author =	 {Baker, Siani L.},
  title = 	 {{A new application for explanation-based generalisation
         	   within automated deduction}},
  year = 	 1994,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-327}
}

@TechReport{UCAM-CL-TR-328,
  author =	 {Curzon, Paul},
  title = 	 {{The formal verification of the Fairisle ATM switching
         	   element: an overview}},
  year = 	 1994,
  month = 	 mar,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-328}
}

@TechReport{UCAM-CL-TR-329,
  author =	 {Curzon, Paul},
  title = 	 {{The formal verification of the Fairisle ATM switching
         	   element}},
  year = 	 1994,
  month = 	 mar,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-329}
}

@TechReport{UCAM-CL-TR-330,
  author =	 {Wellner, Pierre David},
  title = 	 {{Interacting with paper on the DigitalDesk}},
  year = 	 1994,
  month = 	 mar,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-330.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {In the 1970's Xerox PARC developed the ``desktop
            	  metaphor,'' which made computers easy to use by making
            	  them look and act like ordinary desks and paper. This led
            	  visionaries to predict the ``paperless office'' would
            	  dominate within a few years, but the trouble with this
            	  prediction is that people like paper too much. It is
            	  portable, tactile, universally accepted, and easier to
            	  read than a screen. Today, we continue to use paper, and
            	  computers produce more of it than they replace.
            	  
            	  Instead of trying to use computers to replace paper, the
            	  DigitalDesk takes the opposite approach. It keeps the
            	  paper, but uses computers to make it more powerful. It
            	  provides a Computer Augmented Environment for paper.
            	  
            	  The DigitalDesk is built around an ordinary physical desk
            	  and can be used as such, but it has extra capabilities. A
            	  video camera is mounted above the desk, pointing down at
            	  the work surface. This camera's output is fed through a
            	  system that can detect where the user is pointing, and it
            	  can read documents that are placed on the desk. A
            	  computer-driven electronic projector is also mounted
            	  above the desk, allowing the system to project electronic
            	  objects onto the work surface and onto real paper
            	  documents --- something that can't be done with flat
            	  display panels or rear-projection. The system is called
            	  DigitalDesk because it allows pointing with the fingers.
            	  
            	  Several applications have been prototyped on the
            	  DigitalDesk. The first was a calculator where a sheet of
            	  paper such as an annual report can be placed on the desk
            	  allowing the user to point at numbers with a finger or
            	  pen. The camera reads the numbers off the paper,
            	  recognizes them, and enters them into the display for
            	  further calculations. Another is a translation system
            	  which allows users to point at unfamiliar French words to
            	  get their English definitions projected down next to the
            	  paper. A third is a paper-based paint program
            	  (PaperPaint) that allows users to sketch on paper using
            	  traditional tools, but also be able to select and paste
            	  these sketches with the camera and projector to create
            	  merged paper and electronic documents. A fourth
            	  application is the DoubleDigitalDesk, which allows remote
            	  colleagues to ``share'' their desks, look at each other's
            	  paper documents and sketch on them remotely.
            	  
            	  This dissertation introduces the concept of Computer
            	  Augmented Environments, describes the DigitalDesk and
            	  applications for it, and discusses some of the key
            	  implementation issues that need to be addressed to make
            	  this system work. It describes a toolkit for building
            	  DigitalDesk applications, and it concludes with some more
            	  ideas for future work.},
  number = 	 {UCAM-CL-TR-330}
}

@TechReport{UCAM-CL-TR-331,
  author =	 {Adly, Noha and Kumar, Akhil},
  title = 	 {{HPP: a hierarchical propagation protocol for large scale
         	   replication in wide area networks}},
  year = 	 1994,
  month = 	 mar,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-331}
}

@TechReport{UCAM-CL-TR-332,
  author =	 {Evers, David Martin},
  title = 	 {{Distributed computing with objects}},
  year = 	 1994,
  month = 	 mar,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-332}
}

@TechReport{UCAM-CL-TR-333,
  author =	 {Bierman, G.M.},
  title = 	 {{What is a categorical model of intuitionistic linear
         	   logic?}},
  year = 	 1994,
  month = 	 apr,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-333}
}

@TechReport{UCAM-CL-TR-334,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{A concrete final coalgebra theorem for ZF set theory}},
  year = 	 1994,
  month = 	 may,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-334.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {A special final coalgebra theorem, in the style of Aczel
            	  (1988), is proved within standard Zermelo-Fraenkel set
            	  theory. Aczel's Anti-Foundation Axiom is replaced by a
            	  variant definition of function that admits
            	  non-well-founded constructions. Variant ordered pairs and
            	  tuples, of possibly infinite length, are special cases of
            	  variant functions. Analogues of Aczel's Solution and
            	  Substitution Lemmas are proved in the style of Rutten and
            	  Turi (1993).
            	  
            	  The approach is less general than Aczel's;
            	  non-well-founded objects can be modelled only using the
            	  variant tuples and functions. But the treatment of
            	  non-well-founded objects is simple and concrete. The
            	  final coalgebra of a functor is its greatest fixedpoint.
            	  The theory is intended for machine implementation and a
            	  simple case of it is already implemented using the
            	  theorem prover Isabelle.},
  number = 	 {UCAM-CL-TR-334}
}

@TechReport{UCAM-CL-TR-335,
  author =	 {Jones, G.J.F. and Foote, J.T. and Sp{\"a}rck Jones, K. and
          	  Young, S.J.},
  title = 	 {{Video mail retrieval using voice: report on keyword
         	   definition and data collection (deliverable report on VMR
         	   task No.~1)}},
  year = 	 1994,
  month = 	 apr,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-335.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This report describes the rationale, design, collection
            	  and basic statistics of the initial training and test
            	  database for the Cambridge Video Mail Retrieval (VMR)
            	  project. This database is intended to support both
            	  training for the wordspotting processes and testing for
            	  the document searching methods using these that are being
            	  developed for the project's message retrieval task.},
  number = 	 {UCAM-CL-TR-335}
}

@TechReport{UCAM-CL-TR-336,
  author =	 {Hilken, Barnaby P.},
  title = 	 {{Towards a proof theory of rewriting: the simply-typed
         	   2-$\lambda$ calculus}},
  year = 	 1994,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-336}
}

@TechReport{UCAM-CL-TR-337,
  author =	 {Boulton, Richard John},
  title = 	 {{Efficiency in a fully-expansive theorem prover}},
  year = 	 1994,
  month = 	 may,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-337.dvi.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The HOL system is a fully-expansive theorem prover:
            	  Proofs generated in the system are composed of
            	  applications of the primitive inference rules of the
            	  underlying logic. This has two main advantages. First,
            	  the soundness of the system depends only on the
            	  implementations of the primitive rules. Second, users can
            	  be given the freedom to write their own proof procedures
            	  without the risk of making the system unsound. A full
            	  functional programming language is provided for this
            	  purpose. The disadvantage with the approach is that
            	  performance is compromised. This is partly due to the
            	  inherent cost of fully expanding a proof but, as
            	  demonstrated in this thesis, much of the observed
            	  inefficiency is due to the way the derived proof
            	  procedures are written.
            	  
            	  This thesis seeks to identify sources of non-inherent
            	  inefficiency in the HOL system and proposes some
            	  general-purpose and some specialised techniques for
            	  eliminating it. One area that seems to be particularly
            	  amenable to optimisation is equational reasoning. This is
            	  significant because equational reasoning constitutes
            	  large portions of many proofs. A number of techniques are
            	  proposed that transparently optimise equational
            	  reasoning. Existing programs in the HOL system require
            	  little or no modification to work faster.
            	  
            	  The other major contribution of this thesis is a
            	  framework in which part of the computation involved in
            	  HOL proofs can be postponed. This enables users to make
            	  better use of their time. The technique exploits a form
            	  of lazy evaluation. The critical feature is the
            	  separation of the code that generates the structure of a
            	  theorem from the code that justifies it logically.
            	  Delaying the justification allows some non-local
            	  optimisations to be performed in equational reasoning.
            	  None of the techniques sacrifice the security of the
            	  fully-expansive approach.
            	  
            	  A decision procedure for a subset of the theory of linear
            	  arithmetic is used to illustrate many of the techniques.
            	  Decision procedures for this theory are commonplace in
            	  theorem provers due to the importance of arithmetic
            	  reasoning. The techniques described in the thesis have
            	  been implemented and execution times are given. The
            	  implementation of the arithmetic procedure is a major
            	  contribution in itself. For the first time, users of the
            	  HOL system are able to prove many arithmetic lemmas
            	  automatically in a practical amount of time (typically a
            	  second or two).
            	  
            	  The applicability of the techniques to other
            	  fully-expansive theorem provers and possible extensions
            	  of the ideas are considered.},
  number = 	 {UCAM-CL-TR-337}
}

@TechReport{UCAM-CL-TR-338,
  author =	 {Wu, Zhixue},
  title = 	 {{A new approach to implementing atomic data types}},
  year = 	 1994,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-338}
}

@TechReport{UCAM-CL-TR-339,
  author =	 {Logan, Brian and Reece, Steven and Cawsey, Alison and
          	  Galliers, Julia and Sp{\"a}rck Jones, Karen},
  title = 	 {{Belief revision and dialogue management in information
         	   retrieval}},
  year = 	 1994,
  month = 	 may,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-339.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This report describes research to evaluate a theory of
            	  belief revision proposed by Galliers in the context of
            	  information-seeking interaction as modelled by Belkin,
            	  Brooks and Daniels and illustrated by user-librarian
            	  dialogues. The work covered the detailed assessment and
            	  development, and computational implementation and
            	  testing, of both the belief revision theory and the
            	  information retrieval model. Some features of the belief
            	  theory presented problems, and the original `multiple
            	  expert' retrieval model had to be drastically modified to
            	  support rational dialogue management. But the
            	  experimental results showed that the characteristics of
            	  literature seeking interaction could be successfully
            	  captured by the belief theory, exploiting important
            	  elements of the retrieval model. Thus, though the
            	  system's knowledge and dialogue performance were very
            	  limited, it provides a useful base for further research.
            	  The report presents all aspects of the research in
            	  detail, with particular emphasis on the implementation of
            	  belief and intention revision, and the integration of
            	  revision with domain reasoning and dialogue interaction.},
  number = 	 {UCAM-CL-TR-339}
}

@TechReport{UCAM-CL-TR-340,
  author =	 {Hyden, Eoin Andrew},
  title = 	 {{Operating system support for quality of service}},
  year = 	 1994,
  month = 	 jun,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-340.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The deployment of high speed, multiservice networks
            	  within the local area has meant that it has become
            	  possible to deliver continuous media data to a general
            	  purpose workstation. This, in conjunction with the
            	  increasing speed of modern microprocessors, means that it
            	  is now possible to write application programs which
            	  manipulate continuous media in real-time. Unfortunately,
            	  current operating systems do not provide the resource
            	  management facilities which are required to ensure the
            	  timely execution of such applications.
            	  
            	  This dissertation presents a flexible resource management
            	  paradigm, based on the notion of Quality of Service, with
            	  which it is possible to provide the scheduling support
            	  required by continuous media applications. The mechanisms
            	  which are required within an operating system to support
            	  this paradigm are described, and the design and
            	  implementation of a prototypical kernel which implements
            	  them is presented.
            	  
            	  It is shown that, by augmenting the interface between an
            	  application and the operating system, the application can
            	  be informed of varying resource availabilities, and can
            	  make use of this information to vary the quality of its
            	  results. In particular an example decoder application is
            	  presented, which makes use of such information and
            	  exploits some of the fundamental properties of continuous
            	  media data to trade video image quality for the amount of
            	  processor time which it receives.},
  number = 	 {UCAM-CL-TR-340}
}

@TechReport{UCAM-CL-TR-341,
  author =	 {Bates, John},
  title = 	 {{Presentation support for distributed multimedia
         	   applications}},
  year = 	 1994,
  month = 	 jun,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-341.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-341}
}

@TechReport{UCAM-CL-TR-342,
  author =	 {Freeman, Stephen Martin Guy},
  title = 	 {{An architecture for distributed user interfaces}},
  year = 	 1994,
  month = 	 jul,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-342}
}

@TechReport{UCAM-CL-TR-344,
  author =	 {Turner, Martin John},
  title = 	 {{The contour tree image encoding technique and file format}},
  year = 	 1994,
  month = 	 jul,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-344}
}

@TechReport{UCAM-CL-TR-345,
  author =	 {Baker, Siani L.},
  title = 	 {{A proof environment for arithmetic with the Omega rule}},
  year = 	 1994,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-345}
}

@TechReport{UCAM-CL-TR-346,
  author =	 {Bierman, G.M.},
  title = 	 {{On intuitionistic linear logic}},
  year = 	 1994,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  abstract = 	 {In this thesis we carry out a detailed study of the
            	  (propositional) intuitionistic fragment of Girard's
            	  linear logic (ILL). Firstly we give sequent calculus,
            	  natural deduction and axiomatic formulations of ILL. In
            	  particular our natural deduction is different from others
            	  and has important properties, such as closure under
            	  substitution, which others lack. We also study the
            	  process of reduction in all three local formulations,
            	  including a detailed proof of cut elimination. Finally,
            	  we consider translations between Instuitionistic Logic
            	  (IL) and ILL.
            	  
            	  We then consider the linear term calculus, which arises
            	  from applying the Curry-Howard correspondence to the
            	  natural deduction formulation. We show how the various
            	  proof theoretic formulations suggest reductions at the
            	  level of terms. The properties of strong normalization
            	  and confluence are proved for these reduction rules. We
            	  also consider mappings between the extended
            	  $\lambda$-calculus and the linear term calculus.
            	  
            	  Next we consider a categorical model for ILL. We show how
            	  by considering the linear term calculus as an equational
            	  logic, we can derive a model: a linear category. We
            	  consider two alternative models: firstly, one due to
            	  Seely and then one due to Lafont. Surprisingly, we find
            	  that Seely's model is not sound, in that equal terms are
            	  not modelled with equal morphisms. We show how after
            	  adapting Seely's model (by viewing it in a more abstract
            	  setting) it becomes a particular instance of a linear
            	  category. We show how Lafont's model can also be seen as
            	  another particular instance of a linear category. Finally
            	  we consider various categories of coalgebras, whose
            	  construction can be seen as a categorical equivalent of
            	  the translation of IL into ILL.},
  number = 	 {UCAM-CL-TR-346}
}

@TechReport{UCAM-CL-TR-347,
  author =	 {Sp{\"a}rck Jones, Karen},
  title = 	 {{Reflections on TREC}},
  year = 	 1994,
  month = 	 jul,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-347.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This paper discusses the Text REtrieval Conferences
            	  (TREC) programme as a major enterprise in information
            	  retrieval research. It reviews its structure as an
            	  evaluation exercise, characterises the methods of
            	  indexing and retrieval being tested within it in terms of
            	  the approaches to system performance factors these
            	  represent; analyses the test results for solid, overall
            	  conclusions that can be drawn from them; and, in the
            	  light of the particular features of the test data,
            	  assesses TREC both for generally-applicable findings that
            	  emerge from it and for directions it offers for future
            	  research.},
  number = 	 {UCAM-CL-TR-347}
}

@TechReport{UCAM-CL-TR-348,
  author =	 {Hunter, Jane Louise},
  title = 	 {{Integrated sound synchronisation for computer animation}},
  year = 	 1994,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-348}
}

@TechReport{UCAM-CL-TR-349,
  author =	 {Graham, Brian},
  title = 	 {{A HOL interpretation of Noden}},
  year = 	 1994,
  month = 	 sep,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-349}
}

@TechReport{UCAM-CL-TR-350,
  author =	 {Bowen, Jonathan P. and Hinchey, Michael G.},
  title = 	 {{Ten commandments of formal methods}},
  year = 	 1994,
  month = 	 sep,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-350}
}

@TechReport{UCAM-CL-TR-351,
  author =	 {Biswas, Subir Kumar},
  title = 	 {{Handling realtime traffic in mobile networks}},
  year = 	 1994,
  month = 	 sep,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-351.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The rapidly advancing technology of cellular
            	  communication and wireless LAN makes ubiquitous computing
            	  feasible where the mobile users can have access to the
            	  location independent information and the computing
            	  resources. Multimedia networking is another emerging
            	  technological trend of the 1990s and there is an
            	  increasing demand for supporting continuous media traffic
            	  in wireless personal communication environment. In order
            	  to guarantee the strict performance requirements of
            	  realtime traffic, the connection-oriented approaches are
            	  proving to be more efficient compared to the conventional
            	  datagram based networking. This dissertation deals with a
            	  network architecture and its design issues for
            	  implementing the connection-oriented services in a mobile
            	  radio environment.
            	  
            	  The wired backbone of the proposed wireless LAN comprises
            	  of high speed ATM switching elements, connected in a
            	  modular fashion, where the new switches and the user
            	  devices can be dynamically added and reconnected for
            	  maintaining a desired topology. A dynamic reconfiguration
            	  protocol, which can cope with these changing network
            	  topologies, is proposed for the present network
            	  architecture. The details about a prototype
            	  implementation of the protocol and a simulation model for
            	  its performance evaluation are presented.
            	  
            	  CSMA/AED, a single frequency and carrier sensing based
            	  protocol is proposed for the radio medium access
            	  operations. A simulation model is developed in order to
            	  investigate the feasibility of this statistical and
            	  reliable access scheme for the proposed radio network
            	  architecture. The effectiveness of a per-connection
            	  window based flow control mechanism, for the proposed
            	  radio LAN, is also investigated. A hybrid technique is
            	  used, where the medium access and the radio data-link
            	  layers are modelled using the mentioned simulator; an
            	  upper layer end-to-end queueing model, involving flow
            	  dependent servers, is solved using an approximate Mean
            	  Value Analysis technique which is augmented for faster
            	  iterative convergence.
            	  
            	  A distributed location server, for managing mobile users'
            	  location information and for aiding the mobile connection
            	  management tasks, is proposed. In order to hide the
            	  effects of mobility from the non-mobile network entities,
            	  the concept of a per-mobile software entity, known as a
            	  ``representative'', is introduced. A mobile connection
            	  management scheme is also proposed for handling the
            	  end-to-end network layer connections in the present
            	  mobile environment. The scheme uses the representatives
            	  and a novel connection caching technique for providing
            	  the necessary realtime traffic support functionalities.
            	  
            	  A prototype system, comprising of the proposed location
            	  and the connection managers, has been built for
            	  demonstrating the feasibility of the presented
            	  architecture for transporting continuous media traffic. A
            	  set of experiments have been carried out in order to
            	  investigate the impacts of various design decisions and
            	  to identify the performance-critical parts of the design.},
  number = 	 {UCAM-CL-TR-351}
}

@TechReport{UCAM-CL-TR-352,
  author =	 {Benton, P.N.},
  title = 	 {{A mixed linear and non-linear logic: proofs, terms and
         	   models}},
  year = 	 1994,
  month = 	 oct,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-352}
}

@TechReport{UCAM-CL-TR-353,
  author =	 {Gordon, Mike},
  title = 	 {{Merging HOL with set theory}},
  year = 	 1994,
  month = 	 nov,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-353.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Set theory is the standard foundation for mathematics,
            	  but the majority of general purpose mechanized proof
            	  assistants support versions of type theory (higher order
            	  logic). Examples include Alf, Automath, Coq, Ehdm, HOL,
            	  IMPS, Lambda, LEGO, Nuprl, PVS and Veritas. For many
            	  applications type theory works well and provides for
            	  specification the benefits of type-checking that are well
            	  known in programming. However, there are areas where
            	  types get in the way or seem unmotivated. Furthermore,
            	  most people with a scientific or engineering background
            	  already know set theory, whereas type theory may appear
            	  inaccessible and so be an obstacle to the uptake of proof
            	  assistants based on it. This paper describes some
            	  experiments (using HOL) in combining set theory and type
            	  theory; the aim is to get the best of both worlds in a
            	  single system. Three approaches have been tried, all
            	  based on an axiomatically specified type V of ZF-like
            	  sets: (i) HOL is used without any additions besides V;
            	  (ii) an embedding of the HOL logic into V is provided;
            	  (iii) HOL axiomatic theories are automatically translated
            	  into set-theoretic definitional theories. These
            	  approaches are illustrated with two examples: the
            	  construction of lists and a simple lemma in group theory.},
  number = 	 {UCAM-CL-TR-353}
}

@TechReport{UCAM-CL-TR-354,
  author =	 {Agerholm, Sten},
  title = 	 {{Formalising a model of the $\lambda$-calculus in HOL-ST}},
  year = 	 1994,
  month = 	 oct,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-354}
}

@TechReport{UCAM-CL-TR-355,
  author =	 {Wheeler, David and Needham, Roger},
  title = 	 {{Two cryptographic notes}},
  year = 	 1994,
  month = 	 nov,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-355.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {A large block DES-like algorithm
            	  
            	  DES was designed to be slow in software. We give here a
            	  DES type of code which applies directly to single blocks
            	  comprising two or more words of 32 bits. It is thought to
            	  be at least as secure as performing DES separately on two
            	  word blocks, and has the added advantage of not requiring
            	  chaining etc. It is about 8m/(12+2m) times as fast as DES
            	  for an m word block and has a greater gain for Feistel
            	  codes where the number of rounds is greater. We use the
            	  name GDES for the codes we discuss. The principle can be
            	  used on any Feistel code.
            	  
            	  TEA, a Tiny Encryption Algorithm
            	  
            	  We design a short program which will run on most machines
            	  and encypher safely. It uses a large number of iterations
            	  rather than a complicated program. It is hoped that it
            	  can easily be translated into most languages in a
            	  compatible way. The first program is given below. It uses
            	  little set up time and does a weak non linear iteration
            	  enough rounds to make it secure. There are no preset
            	  tables or long set up times. It assumes 32 bit words.},
  number = 	 {UCAM-CL-TR-355}
}

@TechReport{UCAM-CL-TR-356,
  author =	 {Robertson, S.E. and Sp{\"a}rck Jones, K.},
  title = 	 {{Simple, proven approaches to text retrieval}},
  year = 	 1994,
  month = 	 dec,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-356.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This technical note describes straightforward techniques
            	  for document indexing and retrieval that have been
            	  solidly established through extensive testing and are
            	  easy to apply. They are useful for many different types
            	  of text material, are viable for very large files, and
            	  have the advantage that they do not require special
            	  skills or training for searching, but are easy for end
            	  users.},
  number = 	 {UCAM-CL-TR-356}
}

@TechReport{UCAM-CL-TR-357,
  author =	 {Bowen, Jonathan P. and Hinchey, Michael G.},
  title = 	 {{Seven more myths of formal methods}},
  year = 	 1994,
  month = 	 dec,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-357}
}

@TechReport{UCAM-CL-TR-358,
  author =	 {Moore, Simon William},
  title = 	 {{Multithreaded processor design}},
  year = 	 1995,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-358}
}

@TechReport{UCAM-CL-TR-359,
  author =	 {Frost, Jacob},
  title = 	 {{A case study of co-induction in Isabelle}},
  year = 	 1995,
  month = 	 feb,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-359.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The consistency of the dynamic and static semantics for
            	  a small functional programming language was informally
            	  proved by R. Milner and M. Tofte. The notions of
            	  co-inductive definitions and the associated principle of
            	  co-induction played a pivotal role in the proof. With
            	  emphasis on co-induction, the work presented here deals
            	  with the formalisation of this result in the generic
            	  theorem prover Isabelle.},
  number = 	 {UCAM-CL-TR-359}
}

@TechReport{UCAM-CL-TR-360,
  author =	 {Clocksin, W.F.},
  title = 	 {{On the calculation of explicit polymetres}},
  year = 	 1995,
  month = 	 mar,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-360.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Computer scientists take an interest in objects or
            	  events which can be counted, grouped, timed and
            	  synchronised. The computational problems involved with
            	  the interpretation and notation of musical rhythm are
            	  therefore of particular interest, as the most complex
            	  time-stamped structures yet devised by humankind are to
            	  be found in music notation. These problems are brought
            	  into focus when considering explicit polymetric notation,
            	  which is the concurrent use of different time signatures
            	  in music notation. While not in common use the notation
            	  can be used to specify complicated cross-rhythms, simple
            	  versus compound metres, and unequal note values without
            	  the need for tuplet notation. From a computational point
            	  of view, explicit polymetric notation is a means of
            	  specifying synchronisation relationships amongst multiple
            	  time-stamped streams. Human readers of explicit polymetic
            	  notation use the time signatures together with the layout
            	  of barlines and musical events as clues to determine the
            	  performance. However, if the aim is to lay out the
            	  notation (such as might be required by an automatic music
            	  notation processor), the location of barlines and musical
            	  events will be unknown, and it is necessary to calculate
            	  them given only the information conveyed by the time
            	  signatures. Similar problems arise when trying to perform
            	  the notation (i.e. animate the specification) in
            	  real-time. Some problems in the interpretation of
            	  explicit polymetric notation are identified and a
            	  solution is proposed. Two different interpretations are
            	  distinguished, and methods for their automatic
            	  calculation are given. The solution given may be applied
            	  to problems which involve the synchronisation or phase
            	  adjustment of multiple independent threads of
            	  time-stamped objects.},
  number = 	 {UCAM-CL-TR-360}
}

@TechReport{UCAM-CL-TR-361,
  author =	 {Black, Richard John},
  title = 	 {{Explicit network scheduling}},
  year = 	 1995,
  month = 	 apr,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-361.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This dissertation considers various problems associated
            	  with the scheduling and network I/O organisation found in
            	  conventional operating systems for effective support for
            	  multimedia applications which require Quality of Service.
            	  
            	  A solution for these problems is proposed in a
            	  micro-kernel structure. The pivotal features of the
            	  proposed design are that the processing of device
            	  interrupts is performed by user-space processes which are
            	  scheduled by the system like any other, that events are
            	  used for both inter- and intra-process synchronisation,
            	  and the use of a specially developed high performance I/O
            	  buffer management system.
            	  
            	  An evaluation of an experimental implementation is
            	  included. In addition to solving the scheduling and
            	  networking problems addressed, the prototype is shown to
            	  out-perform the Wanda system (a locally developed
            	  micro-kernel) on the same platform.
            	  
            	  This dissertation concludes that it is possible to
            	  construct an operating system where the kernel provides
            	  only the fundamental job of fine grain sharing of the CPU
            	  between processes, and hence synchronisation between
            	  those processes. This enables processes to perform task
            	  specific optimisations; as a result system performance is
            	  enhanced, both with respect to throughput and the meeting
            	  of soft real-time guarantees.},
  number = 	 {UCAM-CL-TR-361}
}

@TechReport{UCAM-CL-TR-362,
  author =	 {Humphrys, Mark},
  title = 	 {{W-learning: competition among selfish Q-learners}},
  year = 	 1995,
  month = 	 apr,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-362.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {W-learning is a self-organising action-selection scheme
            	  for systems with multiple parallel goals, such as
            	  autonomous mobile robots. It uses ideas drawn from the
            	  subsumption architecture for mobile robots (Brooks),
            	  implementing them with the Q-learning algorithm from
            	  reinforcement learning (Watkins). Brooks explores the
            	  idea of multiple sensing-and-acting agents within a
            	  single robot, more than one of which is capable of
            	  controlling the robot on its own if allowed. I introduce
            	  a model where the agents are not only autonomous, but are
            	  in fact engaged in direct competition with each other for
            	  control of the robot. Interesting robots are ones where
            	  no agent achieves total victory, but rather the
            	  state-space is fragmented among different agents. Having
            	  the agents operate by Q-learning proves to be a way to
            	  implement this, leading to a local, incremental algorithm
            	  (W-learning) to resolve competition. I present a sketch
            	  proof that this algorithm converges when the world is a
            	  discrete, finite Markov decision process. For each state,
            	  competition is resolved with the most likely winner of
            	  the state being the agent that is most likely to suffer
            	  the most if it does not win. In this way, W-learning can
            	  be viewed as `fair' resolution of competition. In the
            	  empirical section, I show how W-learning may be used to
            	  define spaces of agent-collections whose action selection
            	  is learnt rather than hand-designed. This is the kind of
            	  solution-space that may be searched with a genetic
            	  algorithm.},
  number = 	 {UCAM-CL-TR-362}
}

@TechReport{UCAM-CL-TR-363,
  author =	 {Stark, Ian},
  title = 	 {{Names and higher-order functions}},
  year = 	 1995,
  month = 	 apr,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-363.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Many functional programming languages rely on the
            	  elimination of `impure' features: assignment to
            	  variables, exceptions and even input/output. But some of
            	  these are genuinely useful, and it is of real interest to
            	  establish how they can be reintroducted in a controlled
            	  way. This dissertation looks in detail at one example of
            	  this: the addition to a functional language of
            	  dynamically generated ``names''. Names are created fresh,
            	  they can be compared with each other and passed around,
            	  but that is all. As a very basic example of ``state'',
            	  they capture the graduation between private and public,
            	  local and global, by their interaction with higher-order
            	  functions.
            	  
            	  The vehicle for this study is the ``nu-calculus'', an
            	  extension of the simply-typed lambda-calculus. The
            	  nu-calculus is equivalent to a certain fragment of
            	  Standard ML, omitting side-effects, exceptions, datatypes
            	  and recursion. Even without all these features, the
            	  interaction of name creation with higher-order functions
            	  can be complex and subtle.
            	  
            	  Various operational and denotational methods for
            	  reasoning about the nu-calculus are developed. These
            	  include a computational metalanguage in the style of
            	  Moggi, which distinguishes in the type system between
            	  values and computations. This leads to categorical models
            	  that use a strong monad, and examples are devised based
            	  on functor categories.
            	  
            	  The idea of ``logical relations'' is used to derive
            	  powerful reasoning methods that capture some of the
            	  distinction between private and public names. These
            	  techniques are shown to be complete for establishing
            	  contextual equivalence between first-order expressions;
            	  they are also used to construct a correspondingly
            	  abstract categorical model.
            	  
            	  All the work with the nu-calculus extends cleanly to
            	  Reduced ML, a larger language that introduces integer
            	  references: mutable storage cells that are dynamically
            	  allocated. It turns out that the step up is quite simple,
            	  and both the computational metalanguage and the sample
            	  categorical models can be reused.},
  number = 	 {UCAM-CL-TR-363}
}

@TechReport{UCAM-CL-TR-364,
  author =	 {Rasmussen, Ole},
  title = 	 {{The Church-Rosser theorem in Isabelle: a proof porting
         	   experiment}},
  year = 	 1995,
  month = 	 apr,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-364.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This paper describes a proof of the Church-Rosser
            	  theorem for the pure lambda-calculus formalised in the
            	  Isabelle theorem prover. The initial version of the proof
            	  is ported from a similar proof done in the Coq proof
            	  assistant by Girard Huet, but a number of optimisations
            	  have been performed. The development involves the
            	  introduction of several inductive and recursive
            	  definitions and thus gives a good presentation of the
            	  inductive package of Isabelle.},
  number = 	 {UCAM-CL-TR-364}
}

@TechReport{UCAM-CL-TR-365,
  author =	 {Benton, P.N. and Bierman, G.M. and de Paiva, V.C.V.},
  title = 	 {{Computational types from a logical perspective I}},
  year = 	 1995,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-365}
}

@TechReport{UCAM-CL-TR-366,
  author =	 {Sp{\"a}rck Jones, K. and Jones, G.J.F. and Foote, J.T. and
          	  Young, S.J.},
  title = 	 {{Retrieving spoken documents: VMR Project experiments}},
  year = 	 1995,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-366}
}

@TechReport{UCAM-CL-TR-367,
  author =	 {Pitts, Andrew M.},
  title = 	 {{Categorical logic}},
  year = 	 1995,
  month = 	 may,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-367.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This document provides an introduction to the
            	  interaction between category theory and mathematical
            	  logic which is slanted towards computer scientists. It
            	  will be a chapter in the forthcoming Volume VI of: S.
            	  Abramsky, D. M. Gabbay, and T. S. E. Maibaum (eds),
            	  ``Handbook of Logic in Computer Science'', Oxford
            	  University Press.},
  number = 	 {UCAM-CL-TR-367}
}

@TechReport{UCAM-CL-TR-368,
  author =	 {Stiller, Burkhard},
  title = 	 {{CogPiT -- configuration of protocols in TIP}},
  year = 	 1995,
  month = 	 jun,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-368.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The variety of upcoming applications in terms of their
            	  performance and Quality-of-Service (QoS) requirements is
            	  increasing. Besides almost well-known applications, such
            	  as teleconferencing, audio- and video-transmissions, even
            	  more contemporary ones, such as medical imaging,
            	  Video-on-Demand, and interactive tutoring systems, are
            	  introduced and applied to existing networks. On the
            	  contrary, traditionally data-oriented applications, such
            	  as file transfer and remote login, are considerably
            	  different in terms of their QoS requirements. Therefore,
            	  the consequences of this evolution effect the
            	  architectures of end-systems, e.g., workstations that
            	  have to be capable of maintaining all different kinds of
            	  multi-media data, and intermediate-systems as well.
            	  
            	  Therefore, a configuration approach of communication
            	  protocols has been developed to support the variety of
            	  applications. This approach offers the possibility to
            	  configure communication protocols automatically depending
            	  on the application requirements expressed in various QoS
            	  parameters. The result, an application-tailored
            	  communication protocol, matches the requested application
            	  requirements as far as possible. Additionally, network
            	  and system resources (NSR) are taken into account for a
            	  well-suited configuration.
            	  
            	  The Configuration of Protocols in TIP is called CogPiT
            	  and is part of the Transport and Internetworking Package
            	  (TIP). As an example, in the TIP environment the
            	  transport protocol TEMPO is used for configuration
            	  purposes.},
  number = 	 {UCAM-CL-TR-368}
}

@TechReport{UCAM-CL-TR-369,
  author =	 {Agerholm, Sten},
  title = 	 {{A comparison of HOL-ST and Isabelle/ZF}},
  year = 	 1995,
  month = 	 jul,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-369.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The use of higher order logic (simple type theory) is
            	  often limited by its restrictive type system. Set theory
            	  allows many constructions on sets that are not possible
            	  on types in higher order logic. This paper presents a
            	  comparison of two theorem provers supporting set theory,
            	  namely HOL-ST and Isabelle/ZF, based on a formalization
            	  of the inverse limit construction of domain theory; this
            	  construction cannot be formalized in higher order logic
            	  directly. We argue that whilst the combination of higher
            	  order logic and set theory in HOL-ST has advantages over
            	  the first order set theory in Isabelle/ZF, the proof
            	  infrastructure of Isabelle/ZF has better support for set
            	  theory proofs than HOL-ST. Proofs in Isabelle/ZF are both
            	  considerably shorter and easier to write.},
  number = 	 {UCAM-CL-TR-369}
}

@TechReport{UCAM-CL-TR-370,
  author =	 {Agerholm, Sten},
  title = 	 {{A package for non-primitive recursive function definitions
         	   in HOL}},
  year = 	 1995,
  month = 	 jul,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-370}
}

@TechReport{UCAM-CL-TR-371,
  author =	 {Wagner, Kim Ritter},
  title = 	 {{LIMINF convergence in $\Omega$-categories}},
  year = 	 1995,
  month = 	 jun,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-371}
}

@TechReport{UCAM-CL-TR-372,
  author =	 {Hild, Stefan G.},
  title = 	 {{A brief history of mobile telephony}},
  year = 	 1995,
  month = 	 jan,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-372}
}

@TechReport{UCAM-CL-TR-373,
  author =	 {Mac{\'\i}as, Benjam{\'\i}n and Pulman, Stephen G.},
  title = 	 {{Natural-language processing and requirements
         	   specifications}},
  year = 	 1995,
  month = 	 jul,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-373}
}

@TechReport{UCAM-CL-TR-374,
  author =	 {Stiller, Burkhard},
  title = 	 {{A framework for QoS updates in a networking environment}},
  year = 	 1995,
  month = 	 jul,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-374.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The support of sufficient Quality-of-Service (QoS) for
            	  applications residing in a distributed environment and
            	  running on top of high performance networks is a
            	  demanding issue. Currently, the areas to provide this
            	  support adequately include communication protocols,
            	  operating systems support, and offered network services.
            	  A configurable approach of communication protocols offers
            	  the needed protocol flexibility to react accordingly on
            	  various different requirements.
            	  
            	  Communication protocols and operating systems have to be
            	  parametrized using internal configuration parameters,
            	  such as window sizes, retry counters, or scheduling
            	  mechanisms, that rely closely on requested
            	  application-oriented or network-dependent QoS, such as
            	  bandwidth or delay. Moreover, these internal parameters
            	  have to be recalculated from time to time due to network
            	  changes (such as congestion or line break-down) or due to
            	  application-specific alterations (such as enhanced
            	  bandwidth requirements or increased reliability) to
            	  adjust a temporary or semi-permanent ``out-of-tune''
            	  service behavior.
            	  
            	  Therefore, a rule-based evaluation and QoS updating
            	  framework for configuration parameters in a networking
            	  environment has been developed. The resulting
            	  ``rulework'' can be used within highly dynamic
            	  environments in a communication subsystem that offers the
            	  possibility to specify for every QoS parameter both a
            	  bounding interval of values and an average value. As an
            	  example, the framework has been integrated in the
            	  Function-based Communication Subsystem (F-CSS).
            	  Especially, an enhanced application service interface is
            	  offered, allowing for the specification of various
            	  QoS-parameters that are used to configure a sufficient
            	  application-tailored communication protocol.},
  number = 	 {UCAM-CL-TR-374}
}

@TechReport{UCAM-CL-TR-375,
  author =	 {Huang, Feng},
  title = 	 {{Restructuring virtual memory to support distributed
         	   computing environments}},
  year = 	 1995,
  month = 	 jul,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-375}
}

@TechReport{UCAM-CL-TR-376,
  author =	 {Roscoe, Timothy},
  title = 	 {{The structure of a multi-service operating system}},
  year = 	 1995,
  month = 	 aug,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-376.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Increases in processor speed and network bandwidth have
            	  led to workstations being used to process multimedia data
            	  in real time. These applications have requirements not
            	  met by existing operating systems, primarily in the area
            	  of resource control: there is a need to reserve
            	  resources, in particular the processor, at a fine
            	  granularity. Furthermore, guarantees need to be
            	  dynamically renegotiated to allow users to reassign
            	  resources when the machine is heavily loaded. There have
            	  been few attempts to provide the necessary facilities in
            	  traditional operating systems, and the internal structure
            	  of such systems makes the implementation of useful
            	  resource control difficult.
            	  
            	  This dissertation presents a way of structuring an
            	  operating system to reduce crosstalk between applications
            	  sharing the machine, and enable useful resource
            	  guarantees to be made: instead of system services being
            	  located in the kernel or server processes, they are
            	  placed as much as possible in client protection domains
            	  and scheduled as part of the client, with communication
            	  between domains only occurring when necessary to enforce
            	  protection and concurrency control. This amounts to
            	  multiplexing the service at as low a level of abstraction
            	  as possible. A mechanism for sharing processor time
            	  between resources is also described. The prototype
            	  Nemesis operating system is used to demonstrate the ideas
            	  in use in a practical system, and to illustrate solutions
            	  to several implementation problems that arise.
            	  
            	  Firstly, structuring tools in the form of typed
            	  interfaces within a single address space are used to
            	  reduce the complexity of the system from the programmer's
            	  viewpoint and enable rich sharing of text and data
            	  between applications.
            	  
            	  Secondly, a scheduler is presented which delivers useful
            	  Quality of Service guarantees to applications in a highly
            	  efficient manner. Integrated with the scheduler is an
            	  inter-domain communication system which has minimal
            	  impact on resource guarantees, and a method of decoupling
            	  hardware interrupts from the execution of device drivers.
            	  
            	  Finally, a framework for high-level inter-domain and
            	  inter-machine communication is described, which goes
            	  beyond object-based RPC systems to permit both Quality of
            	  Service negotiation when a communication binding is
            	  established, and services to be implemented straddling
            	  protection domain boundaries as well as locally and in
            	  remote processes.},
  number = 	 {UCAM-CL-TR-376}
}

@TechReport{UCAM-CL-TR-377,
  author =	 {Paulson, Larry and Grabczewski, Krzysztof},
  title = 	 {{Mechanising set theory: cardinal arithmetic and the axiom
         	   of choice}},
  year = 	 1995,
  month = 	 jul,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-377.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Fairly deep results of Zermelo-Fraenkel (ZF) set theory
            	  have been mechanised using the proof assistant Isabelle.
            	  The results concern cardinal arithmetic and the Axiom of
            	  Choice (AC). A key result about cardinal multiplication
            	  is K*K=K, where K is any infinite cardinal. Proving this
            	  result required developing theories of orders,
            	  order-isomorphisms, order types, ordinal arithmetic,
            	  cardinals, etc.; this covers most of Kunen, Set Theory,
            	  Chapter I. Furthermore, we have proved the equivalence of
            	  7 formulations of the Well-ordering Theorem and 20
            	  formulations of AC; this covers the first two chapters of
            	  Rubin and Rubin, Equivalents of the Axiom of Choice. The
            	  definitions used in the proofs are largely faithful in
            	  style to the original mathematics.},
  number = 	 {UCAM-CL-TR-377}
}

@TechReport{UCAM-CL-TR-378,
  author =	 {Adly, Noha},
  title = 	 {{Performance evaluation of HARP: a hierarchical
         	   asynchronous replication protocol for large scale system}},
  year = 	 1995,
  month = 	 aug,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-378.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-378}
}

@TechReport{UCAM-CL-TR-379,
  author =	 {Paulson, Lawrence},
  title = 	 {{Proceedings of the First Isabelle Users Workshop}},
  year = 	 1995,
  month = 	 sep,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-379}
}

@TechReport{UCAM-CL-TR-380,
  author =	 {Stiller, Burkhard},
  title = 	 {{Quality-of-Service issues in networking environments}},
  year = 	 1995,
  month = 	 sep,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-380.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Quality-of-Service (QoS) issues in networking
            	  environments cover various separate areas and topics.
            	  They include at least the specification of applications
            	  requirements, the definition of network services, QoS
            	  models, resource reservation methods, negotiation and
            	  transformation methods for QoS, and operating system
            	  support for guaranteed services. An embracing approach
            	  for handling, dealing with, and supporting QoS in
            	  different scenarios and technical set-ups is required to
            	  manage sufficiently forthcoming communication and
            	  networking tasks. Modern telecommunication systems
            	  require an integrated architecture for applications,
            	  communication subsystems, and network perspectives to
            	  overcome drawbacks of traditional communication
            	  architectures, such as redundant protocol functionality,
            	  weakly designed interfaces between the end-system and a
            	  network adapter, or impossibility of specifying and
            	  guaranteeing QoS parameter.
            	  
            	  This work contains the discussion of a number of
            	  interconnected QoS issues, e.g., QoS mapping, QoS
            	  negotiation, QoS-based configuration of communication
            	  protocols, or QoS aspects in Asynchronous Transfer Mode
            	  (ATM) signaling protocols, which have been dealt with
            	  during a one-year research fellowship. This report is not
            	  intended to be a complete description of every technical
            	  detail, but tries to provide a brief overall picture of
            	  the emerging and explosively developing QoS issues in
            	  telecommunication systems. Additionally, investigations
            	  of some of these issues are undertaken in a more closer
            	  detail. It is mainly focussed on QoS mapping,
            	  negotiation, and updating in the communication protocol
            	  area.},
  number = 	 {UCAM-CL-TR-380}
}

@TechReport{UCAM-CL-TR-381,
  author =	 {Nimscheck, Uwe Michael},
  title = 	 {{Rendering for free form deformations}},
  year = 	 1995,
  month = 	 oct,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-381}
}

@TechReport{UCAM-CL-TR-382,
  author =	 {Castle, Oliver M.},
  title = 	 {{Synthetic image generation for a multiple-view autostereo
         	   display}},
  year = 	 1995,
  month = 	 oct,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-382}
}

@TechReport{UCAM-CL-TR-383,
  author =	 {Adly, Noha},
  title = 	 {{Management of replicated data in large scale systems}},
  year = 	 1995,
  month = 	 nov,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-383}
}

@TechReport{UCAM-CL-TR-384,
  author =	 {Chuang, Shaw-Cheng},
  title = 	 {{Securing ATM networks}},
  year = 	 1995,
  month = 	 jan,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-384.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This is an interim report on the investigations into
            	  securing Asynchronous Transfer Mode (ATM) networks. We
            	  look at the challenge in providing such a secure ATM
            	  network and identify the important issues in achieving
            	  such goal. In this paper, we discuss the issues and
            	  problems involved and outline some techniques to solving
            	  these problems. The network environment is first examined
            	  and we also consider the correct placement of security
            	  mechanism in such an environment. Following the analysis
            	  of the security requirement, we introduce and describe a
            	  key agile cryptographic device for ATM. The protection of
            	  the ATM data plane is extremely important to provide data
            	  confidentiality and data integrity. Techniques in
            	  providing synchronisation, dynamic key change, dynamic
            	  initialisation vector change and Message Authentication
            	  Code on ATM data, are also being considered. Next, we
            	  discuss the corresponding control functions. A few key
            	  exchange protocols are given as possible candidates for
            	  the establishment of the session key. The impact of such
            	  key exchange protocols on the design of an ATM signalling
            	  protocol has also been examined and security extension to
            	  an existing signalling protocol being discussed. We also
            	  talk about securing other control plane functions such as
            	  NNI routing, Inter-Domain Policy Routing, authorisation
            	  and auditing, firewall and intrusion detection, Byzantine
            	  robustness. Management plane functions are also being
            	  looked at, with discussions on bootstrapping,
            	  authenticated neighbour discovery, ILMI Security, PVC
            	  security, VPI security and ATM Forum management model.},
  number = 	 {UCAM-CL-TR-384}
}

@TechReport{UCAM-CL-TR-385,
  author =	 {Saraswat, Sanjay},
  title = 	 {{Performance evaluation of the Delphi machine}},
  year = 	 1995,
  month = 	 dec,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-385}
}

@TechReport{UCAM-CL-TR-386,
  author =	 {Gordon, Andrew D. and Rees, Gareth D.},
  title = 	 {{Bisimilarity for a first-order calculus of objects with
         	   subtyping}},
  year = 	 1996,
  month = 	 jan,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-386}
}

@TechReport{UCAM-CL-TR-387,
  author =	 {Schwiderski, Scarlet and Herbert, Andrew and Moody, Ken},
  title = 	 {{Monitoring composite events in distributed systems}},
  year = 	 1996,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-387}
}

@TechReport{UCAM-CL-TR-388,
  author =	 {Benton, P.N.},
  title = 	 {{A unified approach to strictness analysis and optimising
         	   transformations}},
  year = 	 1996,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-388}
}

@TechReport{UCAM-CL-TR-389,
  author =	 {Wong, Wai},
  title = 	 {{A proof checked for HOL}},
  year = 	 1996,
  month = 	 mar,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-389}
}

@TechReport{UCAM-CL-TR-390,
  author =	 {Boulton, Richard J.},
  title = 	 {{Syn: a single language for specifiying abstract syntax
         	   tress, lexical analysis, parsing and pretty-printing}},
  year = 	 1996,
  month = 	 mar,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-390.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {A language called Syn is described in which all aspects
            	  of context-free syntax can be specified without
            	  redundancy. The language is essentially an extended BNF
            	  grammar. Unusual features include high-level constructs
            	  for specifying lexical aspects of a language and
            	  specification of precedence by textual order. A system
            	  has been implemented for generating lexers, parsers,
            	  pretty-printers and abstract syntax tree representations
            	  from a Syn specification.},
  number = 	 {UCAM-CL-TR-390}
}

@TechReport{UCAM-CL-TR-391,
  author =	 {Kennedy, Andrew John},
  title = 	 {{Programming languages and dimensions}},
  year = 	 1996,
  month = 	 apr,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-391}
}

@TechReport{UCAM-CL-TR-392,
  author =	 {Nestmann, Uwe and Pierce, Benjamin C.},
  title = 	 {{Decoding choice encodings}},
  year = 	 1996,
  month = 	 apr,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-392}
}

@TechReport{UCAM-CL-TR-393,
  author =	 {Crosby, Simon Andrew},
  title = 	 {{Performance management in ATM networks}},
  year = 	 1996,
  month = 	 apr,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-393.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The Asynchronous Transfer Mode (ATM) has been identified
            	  as the technology of choice amongst high speed
            	  communication networks for its potential to integrate
            	  services with disparate resource needs and timing
            	  constraints. Before it can successfully deliver
            	  integrated services, however, significant problems remain
            	  to be solved. They centre around two major issues. First,
            	  there is a need for a simple, powerful network service
            	  interface capable of meeting the communications needs of
            	  new applications. Second, within the network there is a
            	  need to dynamically control a mix of diverse traffic
            	  types to ensure that they meet their performance
            	  criteria.
            	  
            	  Addressing the first concern, this dissertation argues
            	  that a simple network control interface offers
            	  significant advantages over the traditional, heavyweight
            	  approach of the telecommunications industry. A network
            	  control architecture based on a distributed systems
            	  approach is presented which locates both the network
            	  control functions and its services outside the network.
            	  The network service interface uses the Remote Procedure
            	  Call (RPC) paradigm and enables more complicated service
            	  offerings to be built from the basic primitives. A formal
            	  specification and verification of the user-network
            	  signalling protocol is presented. Implementations of the
            	  architecture, both on Unix and the Wanda micro-kernel,
            	  used on the Fairisle ATM switch, are described. The
            	  implementations demonstrate the feasibility of the
            	  architecture, and feature a high degree of experimental
            	  flexibility. This is exploited in the balance of the
            	  dissertation, which presents the results of a practical
            	  study of network performance under a range of dynamic
            	  control mechanisms.
            	  
            	  Addressing the second concern, results are presented from
            	  a study of the cell delay variation suffered by ATM
            	  connections when multiplexed with real ATM traffic in an
            	  uncontrolled network, and from an investigation of the
            	  expansion of bursts of ATM traffic as a result of
            	  multiplexing. The results are compared with those of
            	  analytical models. Finally, results from a study of the
            	  performance delivered to delay sensitive traffic by
            	  priority and rate based cell scheduling algorithms, and
            	  the loss experienced by different types of traffic under
            	  several buffer allocation strategies are presented.},
  number = 	 {UCAM-CL-TR-393}
}

@TechReport{UCAM-CL-TR-394,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{A simple formalization and proof for the mutilated chess
         	   board}},
  year = 	 1996,
  month = 	 apr,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-394.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The impossibility of tiling the mutilated chess board
            	  has been formalized and verified using Isabelle. The
            	  formalization is concise because it is expressed using
            	  inductive definitions. The proofs are straightforward
            	  except for some lemmas concerning finite cardinalities.
            	  This exercise is an object lesson in choosing a good
            	  formalization. is applicable in a variety of domains.},
  number = 	 {UCAM-CL-TR-394}
}

@TechReport{UCAM-CL-TR-395,
  author =	 {Br{\"a}uner, Torben and de Paiva, Valeria},
  title = 	 {{Cut-elimination for full intuitionistic linear logic}},
  year = 	 1996,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-395}
}

@TechReport{UCAM-CL-TR-396,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{Generic automatic proof tools}},
  year = 	 1996,
  month = 	 may,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-396.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This paper explores a synthesis between two distinct
            	  traditions in automated reasoning: resolution and
            	  interaction. In particular it discusses Isabelle, an
            	  interactive theorem prover based upon a form of
            	  resolution. It aims to demonstrate the value of proof
            	  tools that, compared with traditional resolution systems,
            	  seem absurdly limited. Isabelle's classical reasoner
            	  searches for proofs using a tableau approach. The
            	  reasoner is generic: it accepts rules proved in applied
            	  theories, involving defined connectives. New constants
            	  are not reduced to first-order logic; the reasoner},
  number = 	 {UCAM-CL-TR-396}
}

@TechReport{UCAM-CL-TR-397,
  author =	 {Robi{\v c}, Borut},
  title = 	 {{Optimal routing in 2-jump circulant networks}},
  year = 	 1996,
  month = 	 jun,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-397.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {An algorithm for routing a message along the shortest
            	  path between a pair of processors in 2-jump circulant
            	  (undirected double fixed step) network is given. The
            	  algorithm requires O(d) time for preprocessing, and l =
            	  O(d) routing steps, where l is the distance between the
            	  processors and d is the diameter of the network.},
  number = 	 {UCAM-CL-TR-397}
}

@TechReport{UCAM-CL-TR-398,
  author =	 {Dodgson, N.A. and Moore, J.R.},
  title = 	 {{Design and implementation of an autostereoscopic camera
         	   system}},
  year = 	 1996,
  month = 	 jun,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-398.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {An autostereoscopic display provides the viewer with a
            	  three-dimensional image without the need for special
            	  glasses, and allows the user to look around objects in
            	  the image by moving the head left-right. The
            	  time-multiplexed autostereo display developed at the
            	  University of Cambridge has been in operation since late
            	  1991.
            	  
            	  An autostereoscopic camera system has been designed and
            	  implemented. It is capable of taking video input from up
            	  to sixteen cameras, and multiplexing these into a video
            	  output stream with a pixel rate an order of magnitude
            	  faster than the individual input streams. Testing of the
            	  system with eight cameras and a Cambridge Autostereo
            	  Display has produced excellent live autostereoscopic
            	  video.
            	  
            	  This report describes the design of this camera system
            	  which has been successfully implemented and demonstrated.
            	  Problems which arose during this process are discussed,
            	  and a comparison with similar systems made.},
  number = 	 {UCAM-CL-TR-398}
}

@TechReport{UCAM-CL-TR-399,
  author =	 {Hayton, Richard},
  title = 	 {{OASIS : An open architecture for secure interworking
         	   services}},
  year = 	 1996,
  month = 	 jun,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-399.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {An emerging requirement is for applications and
            	  distributed services to cooperate or inter-operate.
            	  Mechanisms have been devised to hide the heterogeneity of
            	  the host operating systems and abstract the issues of
            	  distribution and object location. However, in order for
            	  systems to inter-operate securely there must also be
            	  mechanisms to hide differences in security policy, or at
            	  least negotiate between them.
            	  
            	  This would suggest that a uniform model of access control
            	  is required. Such a model must be extremely flexible with
            	  respect to the specification of policy, as different
            	  applications have radically different needs. In a widely
            	  distributed environment this situation is exacerbated by
            	  the differing requirements of different organisations,
            	  and in an open environment there is a need to interwork
            	  with organisations using alternative security mechanisms.
            	  
            	  Other proposals for the interworking of security
            	  mechanisms have concentrated on the enforcement of access
            	  policy, and neglected the concerns of freedom of
            	  expression of this policy. For example it is common to
            	  associate each request with a user identity, and to use
            	  this as the only parameter when performing access
            	  control. This work describes an architectural approach to
            	  security. By reconsidering the role of the client and the
            	  server, we may reformulate access control issues in terms
            	  of client naming.
            	  
            	  We think of a client as obtaining a name issued by a
            	  service; either based on credentials already held by the
            	  client, or by delegation from another client. A grammar
            	  has been devised that allows the conditions under which a
            	  client may assume a name to be specified, and the
            	  conditions under which use of the name will be revoked.
            	  This allows complex security policies to be specified
            	  that define how clients of a service may interact with
            	  each other (through election, delegation and revocation),
            	  how clients interact with a service (by invoking
            	  operations or receiving events) and how clients and
            	  services may inter-operate. (For example, a client of a
            	  Login service may become a client of a file service.)
            	  
            	  This approach allows great flexibility when integrating a
            	  number of services, and reduces the mismatch of policies
            	  common in heterogeneous systems. A flexible security
            	  definition is meaningless if not backed by a robust and
            	  efficient implementation. In this thesis we present a
            	  systems architecture that can be implemented efficiently,
            	  but that allows individual services to `fine tune' the
            	  trade-offs between security, efficiency and freedom of
            	  policy expression. The architecture is inherently
            	  distributed and scalable, and includes mechanisms for
            	  rapid and selective revocation of privileges which may
            	  cascade between services and organisations.},
  number = 	 {UCAM-CL-TR-399}
}

@TechReport{UCAM-CL-TR-400,
  author =	 {Schwiderski, Scarlet},
  title = 	 {{Monitoring the behaviour of distributed systems}},
  year = 	 1996,
  month = 	 jul,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-400}
}

@TechReport{UCAM-CL-TR-401,
  author =	 {Bierman, Gavin},
  title = 	 {{A classical linear $\lambda$-calculus}},
  year = 	 1996,
  month = 	 jul,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-401}
}

@TechReport{UCAM-CL-TR-402,
  author =	 {Jones, G.J.F. and Foote, J.T. and Sp{\"a}rck Jones, K. and
          	  Young, S.J.},
  title = 	 {{Video mail retrieval using voice: report on collection of
         	   naturalistic requests and relevance assessments}},
  year = 	 1996,
  month = 	 sep,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-402}
}

@TechReport{UCAM-CL-TR-403,
  author =	 {Barham, Paul Ronald},
  title = 	 {{Devices in a multi-service operating system}},
  year = 	 1996,
  month = 	 oct,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-403.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Increases in processor speed and network and device
            	  bandwidth have led to general purpose workstations being
            	  called upon to process continuous media data in real
            	  time. Conventional operating systems are unable to cope
            	  with the high loads and strict timing constraints
            	  introduced when such applications form part of a
            	  multi-tasking workload. There is a need for the operating
            	  system to provide fine-grained reservation of processor,
            	  memory and I/O resources and the ability to redistribute
            	  these resources dynamically. A small group of operating
            	  systems researchers have recently proposed a
            	  ``vertically-structured'' architecture where the
            	  operating system kernel provides minimal functionality
            	  and the majority of operating system code executes within
            	  the application itself. This structure greatly simplifies
            	  the task of accounting for processor usage by
            	  applications. The prototype Nemesis operating system
            	  embodies these principles and is used as the platform for
            	  this work.
            	  
            	  This dissertation extends the provision of Quality of
            	  Service guarantees to the I/O system by presenting an
            	  architecture for device drivers which minimises crosstalk
            	  between applications. This is achieved by clearly
            	  separating the data-path operations, which require
            	  careful accounting and scheduling, and the infrequent
            	  control-path operations, which require protection and
            	  concurrency control. The approach taken is to abstract
            	  and multiplex the I/O data-path at the lowest level
            	  possible so as to simplify accounting, policing and
            	  scheduling of I/O resources and enable
            	  application-specific use of I/O devices.
            	  
            	  The architecture is applied to several representative
            	  classes of device including network interfaces, network
            	  connected peripherals, disk drives and framestores. Of
            	  these, disks and framestores are of particular interest
            	  since they must be shared at a very fine granularity but
            	  have traditionally been presented to the application via
            	  a window system or file-system with a high-level and
            	  coarse-grained interface.
            	  
            	  A device driver for the framestore is presented which
            	  abstracts the device at a low level and is therefore able
            	  to provide each client with guaranteed bandwidth to the
            	  framebuffer. The design and implementation of a novel
            	  client-rendering window system is then presented which
            	  uses this driver to enable rendering code to be safely
            	  migrated into a shared library within the client.
            	  
            	  A low-level abstraction of a standard disk drive is also
            	  described which efficiently supports a wide variety of
            	  file systems and other applications requiring persistent
            	  storage, whilst providing guaranteed rates of I/O to
            	  individual clients. An extent-based file system is
            	  presented which can provide guaranteed rate file access
            	  and enables clients to optimise for application-specific
            	  access patterns.},
  number = 	 {UCAM-CL-TR-403}
}

@TechReport{UCAM-CL-TR-404,
  author =	 {Shum, Kam Hong},
  title = 	 {{Adaptive parallelism for computing on heterogeneous
         	   clusters}},
  year = 	 1996,
  month = 	 nov,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-404}
}

@TechReport{UCAM-CL-TR-405,
  author =	 {Boulton, Richard J.},
  title = 	 {{A tool to support formal reasoning about computer
         	   languages}},
  year = 	 1996,
  month = 	 nov,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-405.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {A tool to support formal reasoning about computer
            	  languages and specific language texts is described. The
            	  intention is to provide a tool that can build a formal
            	  reasoning system in a mechanical theorem prover from two
            	  specifications, one for the syntax of the language and
            	  one for the semantics. A parser, pretty-printer and
            	  internal representations are generated from the former.
            	  Logical representations of syntax and semantics, and
            	  associated theorem proving tools, are generated from the
            	  combination of the two specifications. The main aim is to
            	  eliminate tedious work from the task of prototyping a
            	  reasoning tool for a computer language, but the abstract
            	  specifications of the language also assist the automation
            	  of proof.},
  number = 	 {UCAM-CL-TR-405}
}

@TechReport{UCAM-CL-TR-406,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{Tool support for logics of programs}},
  year = 	 1996,
  month = 	 nov,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-406.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Proof tools must be well designed if they are to be more
            	  effective than pen and paper. Isabelle supports a range
            	  of formalisms, two of which are described (higher-order
            	  logic and set theory). Isabelle's representation of logic
            	  is influenced by logic programming: its ``logical
            	  variables'' can be used to implement step-wise
            	  refinement. Its automatic proof procedures are based on
            	  search primitives that are directly available to users.
            	  While emphasizing basic concepts, the article also
            	  discusses applications such as an approach to the
            	  analysis of security protocols.},
  number = 	 {UCAM-CL-TR-406}
}

@TechReport{UCAM-CL-TR-407,
  author =	 {Schoenberg, Sebastian},
  title = 	 {{The L4 microkernel on Alpha : Design and implementation}},
  year = 	 1996,
  month = 	 sep,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-407.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The purpose of a microkernel is to cover the lowest
            	  level of the hardware and to provide a more general
            	  platform to operating systems and applications than the
            	  hardware itself. This has made microkernel development
            	  increasingly interesting. Different types of microkernels
            	  have been developed, ranging from kernels which merely
            	  deal with the hardware infterface (Windows NT HAL),
            	  kernels especially for embedded systems (RTEMS), to
            	  kernels for multimedia streams and real time support
            	  (Nemesis) and general purpose kernels (L4, Mach).
            	  
            	  The common opinion that microkernels lead to
            	  deterioration in system performance has been disproved by
            	  recent research. L4 is an example of a fast and small,
            	  multi address space, message-based microkernel, developed
            	  originally for Intel systems only. Based on the L4
            	  interface, which should be as similar as possible on
            	  different platforms, the L4 Alpha version has been
            	  developed.
            	  
            	  This work describes design decisions, implementation and
            	  interfaces of the L4 version for 64-bit Alpha processors.},
  number = 	 {UCAM-CL-TR-407}
}

@TechReport{UCAM-CL-TR-408,
  author =	 {Harrison, John Robert},
  title = 	 {{Theorem proving with the real numbers}},
  year = 	 1996,
  month = 	 nov,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-408.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This thesis discusses the use of the real numbers in
            	  theorem proving. Typically, theorem provers only support
            	  a few `discrete' datatypes such as the natural numbers.
            	  However the availability of the real numbers opens up
            	  many interesting and important application areas, such as
            	  the verification of floating point hardware and hybrid
            	  systems. It also allows the formalization of many more
            	  branches of classical mathematics, which is particularly
            	  relevant for attempts to inject more rigour into computer
            	  algebra systems.
            	  
            	  Our work is conducted in a version of the HOL theorem
            	  prover. We describe the rigorous definitional
            	  construction of the real numbers, using a new version of
            	  Cantor's method, and the formalization of a significant
            	  portion of real analysis. We also describe an advanced
            	  derived decision procedure for the `Tarski subset' of
            	  real algebra as well as some more modest but practically
            	  useful tools for automating explicit calculations and
            	  routine linear arithmetic reasoning.
            	  
            	  Finally, we consider in more detail two interesting
            	  application areas. We discuss the desirability of
            	  combining the rigour of theorem provers with the power
            	  and convenience of computer algebra systems, and explain
            	  a method we have used in practice to achieve this. We
            	  then move on to the verification of floating point
            	  hardware. After a careful discussion of possible
            	  correctness specifications, we report on two case
            	  studies, one involving a transcendental function.
            	  
            	  We aim to show that a theory of real numbers is useful in
            	  practice and interesting in theory, and that the `LCF
            	  style' of theorem proving is well suited to the kind of
            	  work we describe. We hope also to convince the reader
            	  that the kind of mathematics needed for applications is
            	  well within the abilities of current theorem proving
            	  technology.},
  number = 	 {UCAM-CL-TR-408}
}

@TechReport{UCAM-CL-TR-409,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{Proving properties of security protocols by induction}},
  year = 	 1996,
  month = 	 dec,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-409.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Security protocols are formally specified in terms of
            	  traces, which may involve many interleaved protocol runs.
            	  Traces are defined inductively. Protocol descriptions
            	  model accidental key losses as well as attacks. The model
            	  spy can send spoof messages made up of components
            	  decrypted from previous traffic.
            	  
            	  Correctness properties are verified using the proof tool
            	  Isabelle/HOL. Several symmetric-key protocols have been
            	  studied, including Needham-Schroeder, Yahalom and
            	  Otway-Rees. A new attack has been discovered in a variant
            	  of Otway-Rees (already broken by Mao and Boyd).
            	  Assertions concerning secrecy and authenticity have been
            	  proved.
            	  
            	  The approach rests on a common theory of messages, with
            	  three operators. The operator ``parts'' denotes the
            	  components of a set of messages. The operator ``analz''
            	  denotes those parts that can be decrypted with known
            	  keys. The operator ``synth'' denotes those messages that
            	  can be expressed in terms of given components. The three
            	  operators enjoy many algebraic laws that are invaluable
            	  in proofs.},
  number = 	 {UCAM-CL-TR-409}
}

@TechReport{UCAM-CL-TR-410,
  author =	 {Harrison, John},
  title = 	 {{Proof style}},
  year = 	 1997,
  month = 	 jan,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-410.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {We are concerned with how to communicate a mathematical
            	  proof to a computer theorem prover. This can be done in
            	  many ways, while allowing the machine to generate a
            	  completely formal proof object. The most obvious choice
            	  is the amount of guidance required from the user, or from
            	  the machine perspective, the degree of automation
            	  provided. But another important consideration, which we
            	  consider particularly significant, is the bias towards a
            	  `procedural' or `declarative' proof style. We will
            	  explore this choice in depth, and discuss the strengths
            	  and weaknesses of declarative and procedural styles for
            	  proofs in pure mathematics and for verification
            	  applications. We conclude with a brief summary of our own
            	  experiments in trying to combine both approaches.},
  number = 	 {UCAM-CL-TR-410}
}

@TechReport{UCAM-CL-TR-411,
  author =	 {Nesi, Monica},
  title = 	 {{Formalising process calculi in Higher Order Logic}},
  year = 	 1997,
  month = 	 jan,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-411}
}

@TechReport{UCAM-CL-TR-412,
  author =	 {Bierman, G.M.},
  title = 	 {{Observations on a linear PCF (preliminary report)}},
  year = 	 1997,
  month = 	 jan,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-412}
}

@TechReport{UCAM-CL-TR-413,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{Mechanized proofs of security protocols: Needham-Schroeder
         	   with public keys}},
  year = 	 1997,
  month = 	 jan,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-413.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The inductive approach to verifying security protocols,
            	  previously applied to shared-key encryption, is here
            	  applied to the public key version of the
            	  Needham-Schroeder protocol. As before, mechanized proofs
            	  are performed using Isabelle/HOL. Both the original,
            	  flawed version and Lowe's improved version are studied;
            	  the properties proved highlight the distinctions between
            	  the two versions. The results are compared with previous
            	  analyses of the same protocol. The analysis reported
            	  below required only 30 hours of the author's time. The
            	  proof scripts execute in under three minutes.},
  number = 	 {UCAM-CL-TR-413}
}

@TechReport{UCAM-CL-TR-414,
  author =	 {Abadi, Mart{\'\i}n and Gordon, Andrew D.},
  title = 	 {{A calculus for cryptographic protocols : The SPI calculus}},
  year = 	 1997,
  month = 	 jan,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-414.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {We introduce the spi calculus, an extension of the pi
            	  calculus designed for the description and analysis of
            	  cryptographic protocols. We show how to use the spi
            	  calculus, particularly for studying authentication
            	  protocols. The pi calculus (without extension) suffices
            	  for some abstract protocols; the spi calculus enables us
            	  to consider cryptographic issues in more detail. We
            	  represent protocols as processes in the spi calculus and
            	  state their security properties in terms of
            	  coarse-grained notions of protocol equivalence.},
  number = 	 {UCAM-CL-TR-414}
}

@TechReport{UCAM-CL-TR-415,
  author =	 {Pope, Steven Leslie},
  title = 	 {{Application support for mobile computing}},
  year = 	 1997,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-415}
}

@TechReport{UCAM-CL-TR-416,
  author =	 {Syme, Donald},
  title = 	 {{DECLARE: a prototype declarative proof system for higher
         	   order logic}},
  year = 	 1997,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-416}
}

@TechReport{UCAM-CL-TR-417,
  author =	 {Brown, Peter J.C.},
  title = 	 {{Selective mesh refinement for interactive terrain
         	   rendering}},
  year = 	 1997,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  abstract = 	 {Terrain surfaces are often approximated by geometric
            	  meshes to permit efficient rendering. This paper
            	  describes how the complexity of an approximating
            	  irregular mesh can be varied across its domain in order
            	  to minimise the number of displayed facets while ensuring
            	  that the rendered surface meets pre-determined resolution
            	  requirements. We first present a generalised scheme to
            	  represent a mesh over a continuous range of resolutions
            	  using the output from conventional single-resolution
            	  approximation methods. We then describe an algorithm
            	  which extracts a surface from this representation such
            	  that the resolution of the surface is enhanced only in
            	  specific areas of interest. We prove that the extracted
            	  surface is complete, minimal, satisfies the given
            	  resolution constraints and meets the Delaunay
            	  triangulation criterion if possible. In addition, we
            	  present a method of performing smooth visual transitions
            	  between selectively-refined meshes to permit efficient
            	  animation of a terrain scene.
            	  
            	  A HTML version of that report is at
            	  http://www.cl.cam.ac.uk/research/rainbow/publications/pjcb/tr417/},
  number = 	 {UCAM-CL-TR-417}
}

@TechReport{UCAM-CL-TR-418,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{Mechanized proofs for a recursive authentication protocol}},
  year = 	 1997,
  month = 	 mar,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-418.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {A novel protocol has been formally analyzed using the
            	  prover Isabelle/HOL, following the inductive approach
            	  described in earlier work. There is no limit on the
            	  length of a run, the nesting of messages or the number of
            	  agents involved. A single run of the protocol delivers
            	  session keys for all the agents, allowing neighbours to
            	  perform mutual authentication. The basic security theorem
            	  states that session keys are correctly delivered to
            	  adjacent pairs of honest agents, regardless of whether
            	  other agents in the chain are compromised. The protocol's
            	  complexity caused some difficulties in the specification
            	  and proofs, but its symmetry reduced the number of
            	  theorems to prove.},
  number = 	 {UCAM-CL-TR-418}
}

@TechReport{UCAM-CL-TR-419,
  author =	 {Stafford-Fraser, James Quentin},
  title = 	 {{Video-augmented environments}},
  year = 	 1997,
  month = 	 apr,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-419.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {In the future, the computer will be thought of more as
            	  an assistant than as a tool, and users will increasingly
            	  expect machines to make decisions on their behalf. As
            	  with a human assistant, a machine's ability to make
            	  informed choices will often depend on the extent of its
            	  knowledge of activities in the world around it. Equipping
            	  personal computers with a large number of sensors for
            	  monitoring their environment is, however, expensive and
            	  inconvenient, and a preferable solution would involve a
            	  small number of input devices with a broad scope of
            	  application. Video cameras are ideally suited to many
            	  realworld monitoring applications for this reason. In
            	  addition, recent reductions in the manufacturing costs of
            	  simple cameras will soon make their widespread deployment
            	  in the home and office economically viable. The use of
            	  video as an input device also allows the creation of new
            	  types of user-interface, more suitable in some
            	  circumstances than those afforded by the conventional
            	  keyboard and mouse.
            	  
            	  This thesis examines some examples of these
            	  `Video-Augmented Environments' and related work, and then
            	  describes two applications in detail. The first, a
            	  `software cameraman', uses the analysis of one video
            	  stream to control the display of another. The second,
            	  `BrightBoard', allows a user to control a computer by
            	  making marks on a conventional whiteboard, thus
            	  `augmenting' the board with many of the facilities common
            	  to electronic documents, including the ability to fax,
            	  save, print and email the image of the board. The
            	  techniques which were found to be useful in the
            	  construction of these applications are common to many
            	  systems which monitor real-world video, and so they were
            	  combined in a toolkit called `Vicar'. This provides an
            	  architecture for `video plumbing', which allows standard
            	  videoprocessing components to be connected together under
            	  the control of a scripting language. It is a single
            	  application which can be programmed to create a variety
            	  of simple Video-Augmented Environments, such as those
            	  described above, without the need for any recompilation,
            	  and so should simplify the construction of such
            	  applications in the future. Finally, opportunities for
            	  further exploration on this theme are discussed.},
  number = 	 {UCAM-CL-TR-419}
}

@TechReport{UCAM-CL-TR-420,
  author =	 {Sewell, Jonathan Mark},
  title = 	 {{Managing complex models for computer graphics}},
  year = 	 1997,
  month = 	 apr,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-420.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Three-dimensional computer graphics is becoming more
            	  common as increasing computational power becomes more
            	  readily available. Although the images that can be
            	  produced are becoming more complex, users' expectations
            	  continue to grow. This dissertation examines the changes
            	  in computer graphics software that will be needed to
            	  support continuing growth in complexity, and proposes
            	  techniques for tackling the problems that emerge.
            	  
            	  Increasingly complex models will involve longer rendering
            	  times, higher memory requirements, longer data transfer
            	  periods and larger storage capacities. Furthermore, even
            	  greater demands will be placed on the constructors of
            	  such models. This dissertation aims to describe how to
            	  construct scalable systems which can be used to visualise
            	  models of any size without requiring dedicated hardware.
            	  This is achieved by controlling the quality of the
            	  results, and hence the costs incurred. In addition, the
            	  use of quality controls can become a tool to help users
            	  handle the large volume of information arising from
            	  complex models.
            	  
            	  The underlying approach is to separate the model from the
            	  graphics application which uses it, so that the model
            	  exists independently. By doing this, an application is
            	  free to access only the data which is required at any
            	  given time. For the application to function in this
            	  manner, the data must be in an appropriate form. To
            	  achieve this, approximation hierarchies are defined as a
            	  suitable new model structure. These utilise multiple
            	  representations of both objects and groups of objects at
            	  all levels in the model.
            	  
            	  In order to support such a structure, a novel method is
            	  proposed for rapidly constructing simplified
            	  representations of groups of complex objects. By
            	  calculating a few geometrical attributes, it is possible
            	  to generate replacement objects that preserve important
            	  aspects of the originals. Such objects, once placed into
            	  an approximation hierarchy, allow rapid loading and
            	  rendering of large portions of a model. Extensions to
            	  rendering algorithms are described that take advantage of
            	  this structure.
            	  
            	  The use of multiple representations encompasses not only
            	  different quality levels, but also different storage
            	  formats and types of objects. It provides a framework
            	  within which such aspects are hidden from the user,
            	  facilitating the sharing and re-use of objects. A model
            	  manager is proposed as a means of encapsulating these
            	  mechanisms. This software gives, as far as possible, the
            	  illusion of direct access to the whole complex model,
            	  while at the same time making the best use of the limited
            	  resources available.},
  number = 	 {UCAM-CL-TR-420}
}

@TechReport{UCAM-CL-TR-421,
  author =	 {Norrish, Michael},
  title = 	 {{An abstract dynamic semantics for C}},
  year = 	 1997,
  month = 	 may,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-421.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This report is a presentation of a formal semantics for
            	  the C programming language. The semantics has been
            	  defined operationally in a structured semantics style and
            	  covers the bulk of the core of the language. The
            	  semantics has been developed in a theorem prover (HOL),
            	  where some expected consequences of the language
            	  definition},
  number = 	 {UCAM-CL-TR-421}
}

@TechReport{UCAM-CL-TR-422,
  author =	 {Rowstron, Antony},
  title = 	 {{Using the BONITA primitives: a case study}},
  year = 	 1997,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-422}
}

@TechReport{UCAM-CL-TR-423,
  author =	 {MacDorman, Karl F.},
  title = 	 {{Symbol grounding : Learning categorical and sensorimotor
         	   predictions for coordination in autonomous robots}},
  year = 	 1997,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-423}
}

@TechReport{UCAM-CL-TR-424,
  author =	 {Massacci, Fabio},
  title = 	 {{Simplification with renaming: a general proof technique
         	   for tableau and sequent-based provers}},
  year = 	 1997,
  month = 	 may,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-424.dvi.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-424}
}

@TechReport{UCAM-CL-TR-425,
  author =	 {Lamport, Leslie and Paulson, Lawrence C.},
  title = 	 {{Should your specification language be typed?}},
  year = 	 1997,
  month = 	 may,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-425.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Most specification languages have a type system. Type
            	  systems are hard to get right, and getting them wrong can
            	  lead to inconsistencies. Set theory can serve as the
            	  basis for a specification language without types. This
            	  possibility, which has been widely overlooked, offers
            	  many advantages. Untyped set theory is simple and is more
            	  flexible than any simple typed formalism. Polymorphism,
            	  overloading, and subtyping can make a type system more
            	  powerful, but at the cost of increased complexity, and
            	  such refinements can never attain the flexibility of
            	  having no types at all. Typed formalisms have advantages
            	  too, stemming from the power of mechanical type checking.
            	  While types serve little purpose in hand proofs, they do
            	  help with mechanized proofs. In the absence of
            	  verification, type checking can catch errors in
            	  specifications. It may be possible to have the best of
            	  both worlds by adding typing annotations to an untyped
            	  specification language.
            	  
            	  We consider only specification languages, not programming
            	  languages.},
  number = 	 {UCAM-CL-TR-425}
}

@TechReport{UCAM-CL-TR-426,
  author =	 {Humphrys, Mark},
  title = 	 {{Action selection methods using reinforcement learning}},
  year = 	 1997,
  month = 	 jun,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-426.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The Action Selection problem is the problem of run-time
            	  choice between conflicting and heterogenous goals, a
            	  central problem in the simulation of whole creatures (as
            	  opposed to the solution of isolated uninterrupted tasks).
            	  This thesis argues that Reinforcement Learning has been
            	  overlooked in the solution of the Action Selection
            	  problem. Considering a decentralised model of mind, with
            	  internal tension and competition between selfish
            	  behaviors, this thesis introduces an algorithm called
            	  ``W-learning'', whereby different parts of the mind
            	  modify their behavior based on whether or not they are
            	  succeeding in getting the body to execute their actions.
            	  This thesis sets W-learning in context among the
            	  different ways of exploiting Reinforcement Learning
            	  numbers for the purposes of Action Selection. It is a
            	  `Minimize the Worst Unhappiness' strategy. The different
            	  methods are tested and their strengths and weaknesses
            	  analysed in an artificial world.},
  number = 	 {UCAM-CL-TR-426}
}

@TechReport{UCAM-CL-TR-427,
  author =	 {Syme, Don},
  title = 	 {{Proving Java type soundness}},
  year = 	 1997,
  month = 	 jun,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-427}
}

@TechReport{UCAM-CL-TR-428,
  author =	 {Harrison, John},
  title = 	 {{Floating point verification in HOL Light: the exponential
         	   function}},
  year = 	 1997,
  month = 	 jun,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-428.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {In that they often embody compact but mathematically
            	  sophisticated algorithms, operations for computing the
            	  common transcendental functions in floating point
            	  arithmetic seem good targets for formal verification
            	  using a mechanical theorem prover. We discuss some of the
            	  general issues that arise in verifications of this class,
            	  and then present a machine-checked verification of an
            	  algorithm for computing the exponential function in
            	  IEEE-754 standard binary floating point arithmetic. We
            	  confirm (indeed strengthen) the main result of a
            	  previously published error analysis, though we uncover a
            	  minor error in the hand proof and are forced to confront
            	  several subtle issues that might easily be overlooked
            	  informally.
            	  
            	  Our main theorem connects the floating point exponential
            	  to its abstract mathematical counterpart. The
            	  specification we prove is that the function has the
            	  correct overflow behaviour and, in the absence of
            	  overflow, the error in the result is less than 0.54 units
            	  in the last place (0.77 if the answer is denormalized)
            	  compared against the exact mathematical exponential
            	  function. The algorithm is expressed in a simple
            	  formalized programming language, intended to be a subset
            	  of real programming and hardware description languages.
            	  It uses underlying floating point operations (addition,
            	  multiplication etc.) that are assumed to conform to the
            	  IEEE-754 standard for binary floating point arithmetic.
            	  
            	  The development described here includes, apart from the
            	  proof itself, a formalization of IEEE arithmetic, a
            	  mathematical semantics for the programming language in
            	  which the algorithm is expressed, and the body of pure
            	  mathematics needed. All this is developed logically from
            	  first principles using the HOL Light prover, which
            	  guarantees strict adherence to simple rules of inference
            	  while allowing the user to perform proofs using
            	  higher-level derived rules. We first present the main
            	  ideas and conclusions, and then collect some technical
            	  details about the prover and the underlying mathematical
            	  theories in appendices.},
  number = 	 {UCAM-CL-TR-428}
}

@TechReport{UCAM-CL-TR-429,
  author =	 {Gordon, Andrew D. and Hankin, Paul D. and Lassen, S{\o}ren
          	  B.},
  title = 	 {{Compilation and equivalence of imperative objects}},
  year = 	 1997,
  month = 	 jun,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-429.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {We adopt the untyped imperative object calculus of Abadi
            	  and Cardelli as a minimal setting in which to study
            	  problems of compilation and program equivalence that
            	  arise when compiling object-oriented languages. We
            	  present both a big-step and a small-step
            	  substitution-based operational semantics for the
            	  calculus. Our first two results are theorems asserting
            	  the equivalence of our substitution-based semantics with
            	  a closure-based semantics like that given by Abadi and
            	  Cardelli. Our third result is a direct proof of the
            	  correctness of compilation to a stack-based abstract
            	  machine via a small-step decompilation algorithm. Our
            	  fourth result is that contextual equivalence of objects
            	  coincides with a form of Mason and Talcott's CIU
            	  equivalence; the latter provides a tractable means of
            	  establishing operational equivalences. Finally, we prove
            	  correct an algorithm, used in our prototype compiler, for
            	  statically resolving method offsets. This is the first
            	  study of correctness of an object-oriented abstract
            	  machine, and of operational equivalence for the
            	  imperative object calculus.},
  number = 	 {UCAM-CL-TR-429}
}

@TechReport{UCAM-CL-TR-430,
  author =	 {Jones, G.J.F. and others},
  title = 	 {{Video mail retrieval using voice : Report on topic
         	   spotting}},
  year = 	 1997,
  month = 	 jul,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-430}
}

@TechReport{UCAM-CL-TR-431,
  author =	 {Richards, Martin},
  title = 	 {{The MCPL programming manual and user guide}},
  year = 	 1997,
  month = 	 jul,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-431}
}

@TechReport{UCAM-CL-TR-432,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{On two formal analyses of the Yahalom protocol}},
  year = 	 1997,
  month = 	 jul,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-432.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The Yahalom protocol is one of those analyzed by Burrows
            	  et al. in the BAN paper. Based upon their analysis, they
            	  have proposed modifications to make the protocol easier
            	  to understand and analyze. Both versions of Yahalom have
            	  now been proved, using Isabelle/HOL, to satisfy strong
            	  security goals. The mathematical reasoning behind these
            	  machine proofs is presented informally.
            	  
            	  The new proofs do not rely on a belief logic; they use an
            	  entirely different formal model, the inductive method.
            	  They confirm the BAN analysis and the advantages of the
            	  proposed modifications. The new proof methods detect more
            	  flaws than BAN and analyze protocols in finer detail,
            	  while remaining broadly consistent with the BAN
            	  principles. In particular, the proofs confirm the
            	  explicitness principle of Abadi and Needham.},
  number = 	 {UCAM-CL-TR-432}
}

@TechReport{UCAM-CL-TR-433,
  author =	 {Richards, Martin},
  title = 	 {{Backtracking algorithms in MCPL using bit patterns and
         	   recursion}},
  year = 	 1997,
  month = 	 jul,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-433}
}

@TechReport{UCAM-CL-TR-434,
  author =	 {Richards, Martin},
  title = 	 {{Demonstration programs for CTL and $\mu$-calculus symbolic
         	   model checking}},
  year = 	 1997,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-434}
}

@TechReport{UCAM-CL-TR-435,
  author =	 {Sewell, Peter},
  title = 	 {{Global/local subtyping for a distributed $\pi$-calculus}},
  year = 	 1997,
  month = 	 aug,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-435.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-435}
}

@TechReport{UCAM-CL-TR-436,
  author =	 {Clocksin, W.F.},
  title = 	 {{A new method for estimating optical flow}},
  year = 	 1997,
  month = 	 nov,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-436}
}

@TechReport{UCAM-CL-TR-437,
  author =	 {Harbison, William S.},
  title = 	 {{Trusting in computer systems}},
  year = 	 1997,
  month = 	 dec,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-437}
}

@TechReport{UCAM-CL-TR-438,
  author =	 {Shi, Feng},
  title = 	 {{An architecture for scalable and deterministic video
         	   servers}},
  year = 	 1997,
  month = 	 nov,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-438.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {A video server is a storage system that can provide a
            	  repository for continuous media (CM) data and sustain CM
            	  stream delivery (playback or recording) through networks.
            	  The voluminous nature of CM data demands a video server
            	  to be scalable in order to serve a large number of
            	  concurrent client requests. In addition, deterministic
            	  services can be provided by a video server for playback
            	  because the characteristics of variable bit rate (VBR)
            	  video can be analysed in advance and used in run-time
            	  admission control (AC) and data retrieval.
            	  
            	  Recent research has made gigabit switches a reality, and
            	  the cost/performance ratio of microprocessors and
            	  standard PCs is dropping steadily. It would be more cost
            	  effective and flexible to use off-the-shelf components
            	  inside a video server with a scalable switched network as
            	  the primary interconnect than to make a special purpose
            	  or massively parallel multiprocessor based video server.
            	  This work advocates and assumes such a scalable video
            	  server structure in which data is striped to multiple
            	  peripherals attached directly to a switched network.
            	  
            	  However, most contemporary distributed file systems do
            	  not support data distribution across multiple networked
            	  nodes, let alone providing quality of service (QoS) to CM
            	  applications at the same time. It is the observation of
            	  this dissertation that the software system framework for
            	  network striped video servers is as important as the
            	  scalable hardware architecture itself. This leads to the
            	  development of a new system architecture, which is
            	  scalable, flexible and QoS aware, for scalable and
            	  deterministic video servers. The resulting srchitecture
            	  is called Cadmus from sCAlable and Deterministic
            	  MUlitmedia Servers.
            	  
            	  Cadmus also provides integrated solutions to AC and
            	  actual QoS enforcement in storage nodes. This is achieved
            	  by considering resources such as CPU buffer, disk, and
            	  network, simultaneously but not independently and by
            	  including both real-time (RT) and non-real-time (NRT)
            	  activities, In addition, the potential to smooth the
            	  variability of VBR videos using read-ahead under client
            	  buffer constraints is identified. A new smoothing
            	  algorithm is presented, analysed, and incorporated into
            	  the Cadmus architecture.
            	  
            	  A prototype implementation of Cadmus has been constructed
            	  based on distributed object computing and hardware
            	  modules directly connected to an Asynchronous Transfer
            	  Mode (ATM) network. Experiments were performed to
            	  evaluate the implementation and demonstrate the utility
            	  and feasibility of the architecture and its AC criteria.},
  number = 	 {UCAM-CL-TR-438}
}

@TechReport{UCAM-CL-TR-439,
  author =	 {Halls, David A.},
  title = 	 {{Applying mobile code to distributed systems}},
  year = 	 1997,
  month = 	 dec,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-439}
}

@TechReport{UCAM-CL-TR-440,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{Inductive analysis of the internet protocol TLS}},
  year = 	 1997,
  month = 	 dec,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-440.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Internet browsers use security protocols to protect
            	  confidential messages. An inductive analysis of TLS (a
            	  descendant of SSL 3.0) has been performed using the
            	  theorem prover Isabelle. Proofs are based on higher-order
            	  logic and make no assumptions concerning beliefs or
            	  finiteness. All the obvious security goals can be proved;
            	  session resumption appears to be secure even if old
            	  session keys have been compromised. The analysis suggests
            	  modest changes to simplify the protocol.
            	  
            	  TLS, even at an abstract level, is much more complicated
            	  than most protocols that researchers have verified.
            	  Session keys are negotiated rather than distributed, and
            	  the protocol has many optional parts. Nevertheless, the
            	  resources needed to verify TLS are modest. The inductive
            	  approach scales up.},
  number = 	 {UCAM-CL-TR-440}
}

@TechReport{UCAM-CL-TR-441,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{A generic tableau prover and its integration with Isabelle}},
  year = 	 1998,
  month = 	 jan,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-441.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {A generic tableau prover has been implemented and
            	  integrated with Isabelle. It is based on leantap but is
            	  much more complicated, with numerous modifications to
            	  allow it to reason with any supplied set of tableau
            	  rules. It has a higher-order syntax in order to support
            	  the binding operators of set theory; unification is
            	  first-order (extended for bound variables in obvious
            	  ways) instead of higher-order, for simplicity.
            	  
            	  When a proof is found, it is returned to Isabelle as a
            	  list of tactics. Because Isabelle verifies the proof, the
            	  prover can cut corners for efficiency's sake without
            	  compromising soundness. For example, it knows almost
            	  nothing about types.},
  number = 	 {UCAM-CL-TR-441}
}

@TechReport{UCAM-CL-TR-442,
  author =	 {Fleuriot, Jacques and Paulson, Lawrence C.},
  title = 	 {{A combination of nonstandard analysis and geometry theorem
         	   proving, with application to Newton's Principia}},
  year = 	 1998,
  month = 	 jan,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-442.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The theorem prover Isabelle is used to formalise and
            	  reproduce some of the styles of reasoning used by Newton
            	  in his Principia. The Principia's reasoning is resolutely
            	  geometric in nature but contains ``infinitesimal''
            	  elements and the presence of motion that take it beyond
            	  the traditional boundaries of Euclidean Geometry. These
            	  present difficulties that prevent Newton's proofs from
            	  being mechanised using only the existing geometry theorem
            	  proving (GTP) techniques.
            	  
            	  Using concepts from Robinson's Nonstandard Analysis (NSA)
            	  and a powerful geometric theory, we introduce the concept
            	  of an infinitesimal geometry in which quantities can be
            	  infinitely small or infinitesimal. We reveal and prove
            	  new properties of this geometry that only hold because
            	  infinitesimal elements are allowed and use them to prove
            	  lemmas and theorems from the Principia.},
  number = 	 {UCAM-CL-TR-442}
}

@TechReport{UCAM-CL-TR-443,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{The inductive approach to verifying cryptographic
         	   protocols}},
  year = 	 1998,
  month = 	 feb,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-443.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Informal arguments that cryptographic protocols are
            	  secure can be made rigorous using inductive definitions.
            	  The approach is based on ordinary predicate calculus and
            	  copes with infinite-state systems. Proofs are generated
            	  using Isabelle/HOL. The human effort required to analyze
            	  a protocol can be as little as a week or two, yielding a
            	  proof script that takes a few minutes to run.
            	  
            	  Protocols are inductively defined as sets of traces. A
            	  trace is a list of communication events, perhaps
            	  comprising many interleaved protocol runs. Protocol
            	  descriptions incorporate attacks and accidental losses.
            	  The model spy knows some private keys and can forge
            	  messages using components decrypted from previous
            	  traffic. Three protocols are analyzed below: Otway-Rees
            	  (which uses shared-key encryption), Needham-Schroeder
            	  (which uses public-key encryption), and a recursive
            	  protocol (which is of variable length).
            	  
            	  One can prove that event ev always precedes event ev$'$
            	  or that property P holds provided X remains secret.
            	  Properties can be proved from the viewpoint of the
            	  various principals: say, if A receives a final message
            	  from B then the session key it conveys is good.},
  number = 	 {UCAM-CL-TR-443}
}

@TechReport{UCAM-CL-TR-444,
  author =	 {Sewell, Peter},
  title = 	 {{From rewrite rules to bisimulation congruences}},
  year = 	 1998,
  month = 	 may,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-444.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-444}
}

@TechReport{UCAM-CL-TR-445,
  author =	 {Roe, Michael and Christianson, Bruce and Wheeler, David},
  title = 	 {{Secure sessions from weak secrets}},
  year = 	 1998,
  month = 	 jul,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-445.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Sometimes two parties who share a weak secret k (such as
            	  a password) wish to share a strong secret s (such as a
            	  session key) without revealing information about k to a
            	  (possibly active) attacker. We assume that both parties
            	  can generate strong random numbers and forget secrets,
            	  and present three protocols for secure strong secret
            	  sharing, based on RSA, Diffie-Hellman and El-Gamal. As
            	  well as being simpler and quicker than their
            	  predecessors, our protocols also have slightly stronger
            	  security properties: in particular, they make no
            	  cryptographic use of s and so impose no subtle
            	  restrictions upon the use which is made of s by other
            	  protocols.},
  number = 	 {UCAM-CL-TR-445}
}

@TechReport{UCAM-CL-TR-446,
  author =	 {Sp{\"a}rck Jones, K. and Walker, S. and Robertson, S.E.},
  title = 	 {{A probabilistic model of information and retrieval:
         	   development and status}},
  year = 	 1998,
  month = 	 aug,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-446.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The paper combines a comprehensive account of the
            	  probabilistic model of retrieval with new systematic
            	  experiments on TREC Programme material. It presents the
            	  model from its foundations through its logical
            	  development to cover more aspects of retrieval data and a
            	  wider range of system functions. Each step in the
            	  argument is matched by comparative retrieval tests, to
            	  provide a single coherent account of a major line of
            	  research. The experiments demonstrate, for a large test
            	  collection, that the probabilistic model is effective and
            	  robust, and that it responds appropriately, with major
            	  improvements in performance, to key features of retrieval
            	  situations.},
  number = 	 {UCAM-CL-TR-446}
}

@TechReport{UCAM-CL-TR-447,
  author =	 {Bella, Giampaolo and Paulson, Lawrence C.},
  title = 	 {{Are timestamps worth the effort? A formal treatment}},
  year = 	 1998,
  month = 	 sep,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-447}
}

@TechReport{UCAM-CL-TR-448,
  author =	 {Bierman, G.M.},
  title = 	 {{A computational interpretation of the $\lambda\mu$
         	   calculus}},
  year = 	 1998,
  month = 	 sep,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-448}
}

@TechReport{UCAM-CL-TR-449,
  author =	 {Kamm{\"u}ller, Florian and Wenzel, Markus},
  title = 	 {{Locales : A sectioning concept for Isabelle}},
  year = 	 1998,
  month = 	 oct,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-449}
}

@TechReport{UCAM-CL-TR-450,
  author =	 {van der Merwe, Jacobus Erasmus},
  title = 	 {{Open service support for ATM}},
  year = 	 1998,
  month = 	 nov,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-450}
}

@TechReport{UCAM-CL-TR-451,
  author =	 {Rooney, Sean},
  title = 	 {{The structure of open ATM control architectures}},
  year = 	 1998,
  month = 	 nov,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-451}
}

@TechReport{UCAM-CL-TR-452,
  author =	 {Kamm{\"u}ller, Florian and Paulson, Lawrence C.},
  title = 	 {{A formal proof of Sylow's theorem : An experiment in
         	   abstract algebra with Isabelle Hol}},
  year = 	 1998,
  month = 	 nov,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-452.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The theorem of Sylow is proved in Isabelle HOL. We
            	  follow the proof by Wielandt that is more general than
            	  the original and uses a non-trivial combinatorial
            	  identity. The mathematical proof is explained in some
            	  detail leading on to the mechanization of group theory
            	  and the necessary combinatorics in Isabelle. We present
            	  the mechanization of the proof in detail giving reference
            	  to theorems contained in an appendix. Some weak points of
            	  the experiment with respect to a natural treatment of
            	  abstract algebraic reasoning give rise to a discussion of
            	  the use of module systems to represent abstract algebra
            	  in theorem provers. Drawing from that, we present
            	  tentative ideas for further research into a section
            	  concept for Isabelle.},
  number = 	 {UCAM-CL-TR-452}
}

@TechReport{UCAM-CL-TR-453,
  author =	 {Norrish, Michael},
  title = 	 {{C formalised in HOL}},
  year = 	 1998,
  month = 	 dec,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-453.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {We present a formal semantics of the C programming
            	  language, covering both the type system and the dynamic
            	  behaviour of programs. The semantics is wide-ranging,
            	  covering most of the language, with its most significant
            	  omission being the C library. Using a structural
            	  operational semantics we specify transition relations for
            	  C's expressions, statements and declarations in higher
            	  order logic.
            	  
            	  The consistency of our definition is assured by its
            	  specification in the HOL theorem prover. With the theorem
            	  prover, we have used the semantics as the basis for a set
            	  of proofs of interesting theorems about C. We investigate
            	  properties of expressions and statements separately.
            	  
            	  In our chapter of results about expressions, we begin
            	  with two results about the interaction between the type
            	  system and the dynamic semantics. We have both type
            	  preservation, that the values produced by expressions
            	  conform to the type predicted for them; and type safety,
            	  that typed expressions will not block, but will either
            	  evaluate to a value, or cause undefined behaviour. We
            	  then also show that two broad classes of expression are
            	  deterministic. This last result is of considerable
            	  practical value as it makes later verification proofs
            	  significantly easier.
            	  
            	  In our chapter of results about statements, we prove a
            	  series of derived rules that provide C with Floyd-Hoare
            	  style ``axiomatic'' rules for verifying properties of
            	  programs. These rules are consequences of the original
            	  semantics, not independently stated axioms, so we can be
            	  sure of their soundness. This chapter also proves the
            	  correctness of an automatic tool for constructing
            	  post-conditions for loops with break and return
            	  statements.
            	  
            	  Finally, we perform some simple verification case
            	  studies, going some way towards demonstrating practical
            	  utility for the semantics and accompanying tools.
            	  
            	  This technical report is substantially the same as the
            	  PhD thesis I submitted in August 1998. The minor
            	  differences between that document and this are
            	  principally improvements suggested by my examiners Andy
            	  Gordon and Tom Melham, whom I thank for their help and
            	  careful reading.},
  number = 	 {UCAM-CL-TR-453}
}

@TechReport{UCAM-CL-TR-454,
  author =	 {Pitts, Andrew M.},
  title = 	 {{Parametric polymorphism and operational equivalence}},
  year = 	 1998,
  month = 	 dec,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-454}
}

@TechReport{UCAM-CL-TR-455,
  author =	 {Bierman, G.M.},
  title = 	 {{Multiple modalities}},
  year = 	 1998,
  month = 	 dec,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-455}
}

@TechReport{UCAM-CL-TR-456,
  author =	 {Ross, Joshua Robert Xavier},
  title = 	 {{An evaluation based approach to process calculi}},
  year = 	 1999,
  month = 	 jan,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-456}
}

@TechReport{UCAM-CL-TR-457,
  author =	 {Gordon, Andrew D. and Hankin, Paul D.},
  title = 	 {{A concurrent object calculus: reduction and typing}},
  year = 	 1999,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-457}
}

@TechReport{UCAM-CL-TR-458,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{Final coalgebras as greatest fixed points in ZF set theory}},
  year = 	 1999,
  month = 	 mar,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-458.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {A special final coalgebra theorem, in the style of Aczel
            	  (1988), is proved within standard Zermelo-Fraenkel set
            	  theory. Aczel's Anti-Foundation Axiom is replaced by a
            	  variant definition of function that admits
            	  non-well-founded constructions. Variant ordered pairs and
            	  tuples, of possibly infinite length, are special cases of
            	  variant functions. Analogues of Aczel's solution and
            	  substitution lemmas are proved in the style of Rutten and
            	  Turi (1993). The approach is less general than Aczel's,
            	  but the treatment of non-well-founded objects is simple
            	  and concrete. The final coalgebra of a functor is its
            	  greatest fixedpoint. Compared with previous work
            	  (Paulson, 1995a), iterated substitutions and solutions
            	  are considered, as well as final coalgebras defined with
            	  respect to parameters. The disjoint sum construction is
            	  replaced by a smoother treatment of urelements that
            	  simplifies many of the derivations. The theory
            	  facilitates machine implementation of recursive
            	  definitions by letting both inductive and coinductive
            	  definitions be represented as fixedpoints. It has already
            	  been applied to the theorem prover Isabelle (Paulson,
            	  1994).},
  number = 	 {UCAM-CL-TR-458}
}

@TechReport{UCAM-CL-TR-459,
  author =	 {Afshar, Mohamad},
  title = 	 {{An open parallel architecture for data-intensive
         	   applications}},
  year = 	 1999,
  month = 	 jul,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-459.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Data-intensive applications consist of both declarative
            	  data-processing parts and imperative computational parts.
            	  For applications such as climate modelling, scale hits
            	  both the computational aspects which are typically
            	  handled in a procedural programming language, and the
            	  data-processing aspects which are handled in a database
            	  query language. Although parallelism has been
            	  successfully exploited in the data-processing parts by
            	  parallel evaluation of database queries associated with
            	  the application, current database query languages are
            	  poor at expressing the computational aspects, which are
            	  also subject to scale.
            	  
            	  This thesis proposes an open architecture that delivers
            	  parallelism shared between the database, system and
            	  application, thus enabling the integration of the
            	  conventionally separated query and non-query components
            	  of a data-intensive application. The architecture is
            	  data-model independent and can be used in a variety of
            	  different application areas including decision-support
            	  applications, which are query based, and complex
            	  applications, which comprise procedural language
            	  statements with embedded queries. The architecture
            	  encompasses a unified model of parallelism and the
            	  realisation of this model in the form of a language
            	  within which it is possible to describe both the query
            	  and non-query components of data-intensive applications.
            	  The language enables the construction of parallel
            	  applications by the hierarchical composition of
            	  platform-independent parallel forms, each of which
            	  implements a form of task or data parallelism. These
            	  forms may be used to determine both query and non-query
            	  actions.
            	  
            	  Queries are expressed in a declarative language based on
            	  ``monoid comprehensions''. The approach of using monoids
            	  to model data types and monoid homomorphisms to iterate
            	  over collection types enables mathematically provable
            	  compile-time optimisations whilst also facilitating
            	  multiple collection types and data type extensibility.
            	  Monoid comprehension programs are automatically
            	  transformed into parallel programs composed of
            	  applications of the parallel forms, one of which is the
            	  ``monoid homomorphism''. This process involves
            	  identifying the parts of a query where task and data
            	  parallelism are available and mapping that parallelism
            	  onto the most suitable form. Data parallelism in queries
            	  is mapped onto a form that implements combining tree
            	  parallelism for query evaluation and dividing tree
            	  parallelism to realise data partitioning. Task
            	  parallelism is mapped onto two separate forms that
            	  implement pipeline and independent parallelism. This
            	  translation process is applied to all comprehension
            	  queries including those in complex applications. The
            	  result is a skeleton program in which both the query and
            	  non-query parts are expressed within a single language.
            	  Expressions in this language are amenable to the
            	  application of optimising skeleton rewrite rules.
            	  
            	  A complete prototype of the decision-support architecture
            	  has been constructed on a 128-cell MIMD parallel
            	  computer. A demonstration of the utility of the query
            	  framework is performed by modelling some of OQL and a
            	  substantial subset of SQL. The system is evaluated for
            	  query speedup with a number of hardware configurations
            	  using a large music catalogue database. The results
            	  obtained show that the implementation delivers the
            	  performance gains expected while offering a convenient
            	  definition of the parallel environment.},
  number = 	 {UCAM-CL-TR-459}
}

@TechReport{UCAM-CL-TR-460,
  author =	 {Bella, Giampaolo},
  title = 	 {{Message reception in the inductive approach}},
  year = 	 1999,
  month = 	 mar,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-460}
}

@TechReport{UCAM-CL-TR-461,
  author =	 {Hurd, Joe},
  title = 	 {{Integrating Gandalf and HOL}},
  year = 	 1999,
  month = 	 mar,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-461.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Gandalf is a first-order resolution theorem-prover,
            	  optimized for speed and specializing in manipulations of
            	  large clauses. In this paper I describe GANDALF TAC, a
            	  HOL tactic that proves goals by calling Gandalf and
            	  mirroring the resulting proofs in HOL. This call can
            	  occur over a network, and a Gandalf server may be set up
            	  servicing multiple HOL clients. In addition, the
            	  translation of the Gandalf proof into HOL fits in with
            	  the LCF model and guarantees logical consistency.},
  number = 	 {UCAM-CL-TR-461}
}

@TechReport{UCAM-CL-TR-462,
  author =	 {Sewell, Peter and Wojciechowski, Pawe{\l} T. and Pierce,
          	  Benjamin C.},
  title = 	 {{Location-independent communication for mobile agents: a
         	   two-level architecture}},
  year = 	 1999,
  month = 	 apr,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-462.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-462}
}

@TechReport{UCAM-CL-TR-463,
  author =	 {Sewell, Peter and Vitek, Jan},
  title = 	 {{Secure composition of insecure components}},
  year = 	 1999,
  month = 	 apr,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-463.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-463}
}

@TechReport{UCAM-CL-TR-464,
  author =	 {Lerner, Boaz and Clocksin, William and Dhanjal, Seema and
          	  Hult{\'e}n, Maj and Bishop, Christipher},
  title = 	 {{Feature representation for the automatic analysis of
         	   fluorescence in-situ hybridization images}},
  year = 	 1999,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-464}
}

@TechReport{UCAM-CL-TR-465,
  author =	 {Lerner, Boaz and Dhanjal, Seema and Hult{\'e}n, Maj},
  title = 	 {{Gelfish -- graphical environment for labelling FISH images}},
  year = 	 1999,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-465}
}

@TechReport{UCAM-CL-TR-466,
  author =	 {Lerner, Boaz and Clocksin, William and Dhanjal, Seema and
          	  Hult{\'e}n, Maj and Bishop, Christipher},
  title = 	 {{Automatic signal classification in fluorescence in-situ
         	   hybridization images}},
  year = 	 1999,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-466}
}

@TechReport{UCAM-CL-TR-467,
  author =	 {Paulson, Lawrence C.},
  title = 	 {{Mechanizing UNITY in Isabelle}},
  year = 	 1999,
  month = 	 jun,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-467.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {UNITY is an abstract formalism for proving properties of
            	  concurrent systems, which typically are expressed using
            	  guarded assignments [Chandy and Misra 1988]. UNITY has
            	  been mechanized in higher-order logic using Isabelle, a
            	  proof assistant. Safety and progress primitives, their
            	  weak forms (for the substitution axiom) and the program
            	  composition operator (union) have been formalized. To
            	  give a feel for the concrete syntax, the paper presents a
            	  few extracts from the Isabelle definitions and proofs. It
            	  discusses a small example, two-process mutual exclusion.
            	  A mechanical theory of unions of programs supports a
            	  degree of compositional reasoning. Original work on
            	  extending program states is presented and then
            	  illustrated through a simple example involving an array
            	  of processes.},
  number = 	 {UCAM-CL-TR-467}
}

@TechReport{UCAM-CL-TR-468,
  author =	 {Wilcox, Stephen Paul},
  title = 	 {{Synthesis of asynchronous circuits}},
  year = 	 1999,
  month = 	 jul,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-468}
}

@TechReport{UCAM-CL-TR-469,
  author =	 {Fleuriot, Jacques D{\'e}sir{\'e}},
  title = 	 {{A combination of geometry theorem proving and nonstandard
         	   analysis, with application to Newton's Principia}},
  year = 	 1999,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-469}
}

@TechReport{UCAM-CL-TR-470,
  author =	 {Kamm{\"u}ller, Florian},
  title = 	 {{Modular reasoning in Isabelle}},
  year = 	 1999,
  month = 	 aug,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-470}
}

@TechReport{UCAM-CL-TR-471,
  author =	 {Brady, Robert M. and Anderson, Ross J. and Ball, Robin C.},
  title = 	 {{Murphy's law, the fitness of evolving species, and the
         	   limits of software reliability}},
  year = 	 1999,
  month = 	 sep,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-471.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {We tackle two problems of interest to the software
            	  assurance community. Firstly, existing models of software
            	  development (such as the waterfall and spiral models) are
            	  oriented towards one-off software development projects,
            	  while the growth of mass market computing has led to a
            	  world in which most software consists of packages which
            	  follow an evolutionary development model. This leads us
            	  to ask whether anything interesting and useful may be
            	  said about evolutionary development. We answer in the
            	  affirmative. Secondly, existing reliability growth models
            	  emphasise the Poisson distribution of individual software
            	  bugs, while the empirically observed reliability growth
            	  for large systems is asymptotically slower than this. We
            	  provide a rigorous explanation of this phenomenon. Our
            	  reliability growth model is inspired by statistical
            	  thermodynamics, but also applies to biological evolution.
            	  It is in close agreement with experimental measurements
            	  of the fitness of an evolving species and the reliability
            	  of commercial software products. However, it shows that
            	  there are significant differences between the evolution
            	  of software and the evolution of species. In particular,
            	  we establish maximisation properties corresponding to
            	  Murphy's law which work to the advantage of a biological
            	  species, but to the detriment of software reliability.},
  number = 	 {UCAM-CL-TR-471}
}

@TechReport{UCAM-CL-TR-472,
  author =	 {Reis, Ben Y.},
  title = 	 {{Simulating music learning with autonomous listening
         	   agents: entropy, ambiguity and context}},
  year = 	 1999,
  month = 	 sep,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-472}
}

@TechReport{UCAM-CL-TR-473,
  author =	 {Ballarin, Clemens},
  title = 	 {{Computer algebra and theorem proving}},
  year = 	 1999,
  month = 	 oct,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-473}
}

@TechReport{UCAM-CL-TR-474,
  author =	 {Lerner, Boaz},
  title = 	 {{A Bayesian methodology and probability density estimation
         	   for fluorescence in-situ hybridization signal
         	   classification}},
  year = 	 1999,
  month = 	 oct,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-474}
}

@TechReport{UCAM-CL-TR-475,
  author =	 {Lerner, Boaz and Lawrence, Neil D.},
  title = 	 {{A comparison of state-of-the-art classification techniques
         	   with application to cytogenetics}},
  year = 	 1999,
  month = 	 oct,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-475}
}

@TechReport{UCAM-CL-TR-476,
  author =	 {Staples, Mark},
  title = 	 {{Linking ACL2 and HOL}},
  year = 	 1999,
  month = 	 nov,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-476}
}

@TechReport{UCAM-CL-TR-477,
  author =	 {Cattani, Gian Luca and Winskel, Glynn},
  title = 	 {{Presheaf models for CCS-like languages}},
  year = 	 1999,
  month = 	 nov,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-477}
}

@TechReport{UCAM-CL-TR-478,
  author =	 {Sewell, Peter and Vitek, Jan},
  title = 	 {{Secure composition of untrusted code: wrappers and
         	   causality types}},
  year = 	 1999,
  month = 	 nov,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-478.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-478}
}

@TechReport{UCAM-CL-TR-479,
  author =	 {Price, Geraint},
  title = 	 {{The interaction between fault tolerance and security}},
  year = 	 1999,
  month = 	 dec,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-479.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This dissertation studies the effects on system design
            	  when including fault tolerance design principles within
            	  security services.
            	  
            	  We start by looking at the changes made to the trust
            	  model within protocol design, and how moving away from
            	  trusted server design principles affects the structure of
            	  the protocol. Taking the primary results from this work,
            	  we move on to study how control in protocol execution can
            	  be used to increase assurances in the actions of
            	  legitimate participants. We study some examples, defining
            	  two new classes of attack, and note that by increasing
            	  client control in areas of protocol execution, it is
            	  possible to overcome certain vulnerabilities.
            	  
            	  We then look at different models in fault tolerance, and
            	  how their adoption into a secure environment can change
            	  the design principles and assumptions made when applying
            	  the models.
            	  
            	  We next look at the application of timing checks in
            	  protocols. There are some classes of timing attack that
            	  are difficult to thwart using existing techniques,
            	  because of the inherent unreliability of networked
            	  communication. We develop a method of converting the
            	  Quality of Service mechanisms built into ATM networks in
            	  order to achieve another layer of protection against
            	  timing attacks.
            	  
            	  We then study the use of primary-backup mechanisms within
            	  server design, as previous work on server replication in
            	  security centres on the use of the state machine approach
            	  for replication, which provides a higher degree of
            	  assurance in system design, but adds complexity.
            	  
            	  We then provide a design for a server to reliably and
            	  securely store objects across a loosely coupled,
            	  distributed environment. The main goal behind this design
            	  was to realise the ability for a client to exert control
            	  over the fault tolerance inherent in the service.
            	  
            	  The main conclusions we draw from our research are that
            	  fault tolerance has a wider application within security
            	  than current practices, which are primarily based on
            	  replicating servers, and clients can exert control over
            	  the protocols and mechanisms to achieve resilience
            	  against differing classes of attack. We promote some new
            	  ideas on how, by challenging the prevailing model for
            	  client-server architectures in a secure environment,
            	  legitimate clients can have greater control over the
            	  services they use. We believe this to be a useful goal,
            	  given that the client stands to lose if the security of
            	  the server is undermined.},
  number = 	 {UCAM-CL-TR-479}
}

@TechReport{UCAM-CL-TR-480,
  author =	 {Gordon, Mike},
  title = 	 {{Programming combinations of deduction and BDD-based
         	   symbolic calculation}},
  year = 	 1999,
  month = 	 dec,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-480}
}

@TechReport{UCAM-CL-TR-481,
  author =	 {Gordon, Mike and Larsen, Ken Friis},
  title = 	 {{Combining the Hol98 proof assistant with the BuDDy BDD
         	   package}},
  year = 	 1999,
  month = 	 dec,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-481}
}

@TechReport{UCAM-CL-TR-482,
  author =	 {Daugman, John},
  title = 	 {{Biometric decision landscapes}},
  year = 	 2000,
  month = 	 jan,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-482.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This report investigates the ``decision landscapes''
            	  that characterize several forms of biometric decision
            	  making. The issues discussed include: (i) Estimating the
            	  degrees-of-freedom associated with different biometrics,
            	  as a way of measuring the randomness and complexity (and
            	  therefore the uniqueness) of their templates. (ii) The
            	  consequences of combining more than one biometric test to
            	  arrive at a decision. (iii) The requirements for
            	  performing identification by large-scale exhaustive
            	  database search, as opposed to mere verification by
            	  comparison against a single template. (iv) Scenarios for
            	  Biometric Key Cryptography (the use of biometrics for
            	  encryption of messages). These issues are considered here
            	  in abstract form, but where appropriate, the particular
            	  example of iris recognition is used as an illustration. A
            	  unifying theme of all four sets of issues is the role of
            	  combinatorial complexity, and its measurement, in
            	  determining the potential decisiveness of biometric
            	  decision making.},
  number = 	 {UCAM-CL-TR-482}
}

@TechReport{UCAM-CL-TR-483,
  author =	 {Bos, Hendrik Jaap},
  title = 	 {{Elastic network control}},
  year = 	 2000,
  month = 	 jan,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-483}
}

@TechReport{UCAM-CL-TR-484,
  author =	 {Tucker, Richard},
  title = 	 {{Automatic summarising and the CLASP system}},
  year = 	 2000,
  month = 	 jan,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-484.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This dissertation discusses summarisers and summarising
            	  in general, and presents CLASP, a new summarising system
            	  that uses a shallow semantic representation of the source
            	  text called a ``predication cohesion graph''.
            	  
            	  Nodes in the graph are ``simple predications''
            	  corresponding to events, states and entities mentioned in
            	  the text; edges indicate related or similar nodes.
            	  Summary content is chosen by selecting some of these
            	  predications according to criteria of ``importance'',
            	  ``representativeness'' and ``cohesiveness''. These
            	  criteria are expressed as functions on the nodes of a
            	  weighted graph. Summary text is produced either by
            	  extracting whole sentences from the source text, or by
            	  generating short, indicative ``summary phrases'' from the
            	  selected predications.
            	  
            	  CLASP uses linguistic processing but no domain knowledge,
            	  and therefore does not restrict the subject matter of the
            	  source text. It is intended to deal robustly with complex
            	  texts that it cannot analyse completely accurately or in
            	  full. Experiments in summarising stories from the Wall
            	  Street Journal suggest there may be a benefit in
            	  identifying important material in a semantic
            	  representation rather than a surface one, but that,
            	  despite the robustness of the source representation,
            	  inaccuracies in CLASP's linguistic analysis can
            	  dramatically affect the readability of its summaries. I
            	  discuss ways in which this and other problems might be
            	  overcome.},
  number = 	 {UCAM-CL-TR-484}
}

@TechReport{UCAM-CL-TR-485,
  author =	 {Stewart, Daryl and VanInwegen, Myra},
  title = 	 {{Three notes on the interpretation of Verilog}},
  year = 	 2000,
  month = 	 jan,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-485}
}

@TechReport{UCAM-CL-TR-486,
  author =	 {Thomas, James Richard},
  title = 	 {{Stretching a point: aspect and temporal discourse}},
  year = 	 2000,
  month = 	 feb,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-486}
}

@TechReport{UCAM-CL-TR-487,
  author =	 {Vos, Tanja and Swierstra, Doaitse},
  title = 	 {{Sequential program composition in UNITY}},
  year = 	 2000,
  month = 	 mar,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-487}
}

@TechReport{UCAM-CL-TR-488,
  author =	 {Bella, Giampaolo and Massacci, Fabio and Paulson, Lawrence
          	  and Tramontano, Piero},
  title = 	 {{Formal verification of card-holder registration in SET}},
  year = 	 2000,
  month = 	 mar,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-488}
}

@TechReport{UCAM-CL-TR-489,
  author =	 {Lee, Jong-Hyeon},
  title = 	 {{Designing a reliable publishing framework}},
  year = 	 2000,
  month = 	 apr,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-489.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Due to the growth of the Internet and the widespread
            	  adoption of easy-to use web browsers, the web provides a
            	  new environment for conventional as well as new
            	  businesses. Publishing on the web is a fundamental and
            	  important means of supporting various activities on the
            	  Internet such as commercial transactions, personal home
            	  page publishing, medical information distribution, public
            	  key certification and academic scholarly publishing.
            	  Along with the dramatic growth of the web, the number of
            	  reported frauds is increasing sharply. Since the Internet
            	  was not originally designed for web publishing, it has
            	  some weaknesses that undermine its reliability.
            	  
            	  How can we rely on web publishing? In order to resolve
            	  this question, we need to examine what makes people
            	  confident when reading conventional publications printed
            	  on paper, to investigate what attacks can erode
            	  confidence in web publishing, and to understand the
            	  nature of publishing in general.
            	  
            	  In this dissertation, we examine security properties and
            	  policy models, and their applicability to publishing. We
            	  then investigate the nature of publishing so that we can
            	  extract its technical requirements. To help us understand
            	  the practical mechanisms which might satisfy these
            	  requirements, some applications of electronic publishing
            	  are discussed and some example mechanisms are presented.
            	  
            	  We conclude that guaranteed integrity, verifiable
            	  authenticity and persistent availability of publications
            	  are required to make web publishing more reliable. Hence
            	  we design a framework that can support these properties.
            	  To analyse the framework, we define a security policy for
            	  web publishing that focuses on the guaranteed integrity
            	  and authenticity of web publications, and then describe
            	  some technical primitives that enable us to achieve our
            	  requirements. Finally, the Jikzi publishing system---an
            	  implementation of our framework---is presented with
            	  descriptions of its architecture and possible
            	  applications.},
  number = 	 {UCAM-CL-TR-489}
}

@TechReport{UCAM-CL-TR-490,
  author =	 {Brown, Peter John Cameron},
  title = 	 {{Selective mesh refinement for rendering}},
  year = 	 2000,
  month = 	 apr,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  abstract = 	 {A key task in computer graphics is the rendering of
            	  complex models. As a result, there exist a large number
            	  of schemes for improving the speed of the rendering
            	  process, many of which involve displaying only a
            	  simplified version of a model. When such a simplification
            	  is generated selectively, i.e. detail is only removed in
            	  specific regions of a model, we term this selective mesh
            	  refinement.
            	  
            	  Selective mesh refinement can potentially produce a model
            	  approximation which can be displayed at greatly reduced
            	  cost while remaining perceptually equivalent to a
            	  rendering of the original. For this reason, the field of
            	  selective mesh refinement has been the subject of
            	  dramatically increased interest recently. The resulting
            	  selective refinement methods, though, are restricted in
            	  both the types of model which they can handle and the
            	  form of output meshes which they can generate.
            	  
            	  Our primary thesis is that a selectively refined mesh can
            	  be produced by combining fragments of approximations to a
            	  model without regard to the underlying approximation
            	  method. Thus we can utilise existing approximation
            	  techniques to produce selectively refined meshes in
            	  n-dimensions. This means that the capabilities and
            	  characteristics of standard approximation methods can be
            	  retained in our selectively refined models.
            	  
            	  We also show that a selectively refined approximation
            	  produced in this manner can be smoothly geometrically
            	  morphed into another selective refinement in order to
            	  satisfy modified refinement criteria. This geometric
            	  morphing is necessary to ensure that detail can be added
            	  and removed from models which are selectively refined
            	  with respect to their impact on the current view frustum.
            	  For example, if a model is selectively refined in this
            	  manner and the viewer approaches the model then more
            	  detail may have to be introduced to the displayed mesh in
            	  order to ensure that it satisfies the new refinement
            	  criteria. By geometrically morphing this introduction of
            	  detail we can ensure that the viewer is not distracted by
            	  ``popping'' artifacts.
            	  
            	  We have developed a novel framework within which these
            	  proposals have been verified. This framework consists of
            	  a generalised resolution-based model representation, a
            	  means of specifying refinement criteria and algorithms
            	  which can perform the selective refinement and geometric
            	  morphing tasks. The framework has allowed us to
            	  demonstrate that these twin tasks can be performed both
            	  on the output of existing approximation techniques and
            	  with respect to a variety of refinement criteria.
            	  
            	  A HTML version of this thesis is at
            	  http://www.cl.cam.ac.uk/research/rainbow/publications/pjcb/thesis/},
  number = 	 {UCAM-CL-TR-490}
}

@TechReport{UCAM-CL-TR-491,
  author =	 {Korhonen, Anna and Gorrell, Genevive and McCarthy, Diana},
  title = 	 {{Is hypothesis testing useful for subcategorization
         	   acquisition?}},
  year = 	 2000,
  month = 	 may,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-491}
}

@TechReport{UCAM-CL-TR-492,
  author =	 {Wojciechowski, Pawe{\l} Tomasz},
  title = 	 {{Nomadic Pict: language and infrastructure design for
         	   mobile computation}},
  year = 	 2000,
  month = 	 jun,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-492.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Mobile agents -- units of executing computation that can
            	  migrate between machines -- are likely to become an
            	  important enabling technology for future distributed
            	  systems. We study the distributed infrastructures
            	  required for location-independent communication between
            	  migrating agents. These infrastructures are problematic:
            	  the choice or design of an infrastructure must be
            	  somewhat application-specific -- any given algorithm will
            	  only have satisfactory performance for some range of
            	  migration and communication behaviour; the algorithms
            	  must be matched to the expected properties (and
            	  robustness demands) of applications and the failure
            	  characteristic of the communication medium. To study this
            	  problem we introduce an agent programming language --
            	  Nomadic Pict. It is designed to allow infrastructure
            	  algorithms to be expressed clearly, as translations from
            	  a high-level language to a lower level. The levels are
            	  based on rigorously-defined process calculi, which
            	  provide sharp levels of abstraction. In this dissertation
            	  we describe the language and use it to develop a
            	  distributed infrastructure for an example application.
            	  The language and examples have been implemented; we
            	  conclude with a description of the compiler and runtime
            	  system.},
  number = 	 {UCAM-CL-TR-492}
}

@TechReport{UCAM-CL-TR-493,
  author =	 {Bella, Giampaolo},
  title = 	 {{Inductive verification of cryptographic protocols}},
  year = 	 2000,
  month = 	 jul,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-493.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The dissertation aims at tailoring Paulson's Inductive
            	  Approach for the analysis of classical cryptographic
            	  protocols towards real-world protocols. The aim is
            	  pursued by extending the approach with new elements (e.g.
            	  timestamps and smart cards), new network events (e.g.
            	  message reception) and more expressive functions (e.g.
            	  agents' knowledge). Hence, the aim is achieved by
            	  analysing large protocols (Kerberos IV and Shoup-Rubin),
            	  and by studying how to specify and verify their goals.
            	  
            	  More precisely, the modelling of timestamps and of a
            	  discrete time are first developed on BAN Kerberos, while
            	  comparing the outcomes with those of the BAN logic. The
            	  machinery is then applied to Kerberos IV, whose
            	  complicated use of session keys requires a dedicated
            	  treatment. Three new guarantees limiting the spy's
            	  abilities in case of compromise of a specific session key
            	  are established. Also, it is discovered that Kerberos IV
            	  is subject to an attack due to the weak guarantees of
            	  confidentiality for the protocol responder.
            	  
            	  We develop general strategies to investigate the goals of
            	  authenticity, key distribution and non-injective
            	  agreement, which is a strong form of authentication.
            	  These strategies require formalising the agents'
            	  knowledge of messages. Two approaches are implemented. If
            	  an agent creates a message, then he knows all components
            	  of the message, including the cryptographic key that
            	  encrypts it. Alternatively, a broad definition of agents'
            	  knowledge can be developed if a new network event,
            	  message reception, is formalised.
            	  
            	  The concept of smart card as a secure device that can
            	  store long-term secrets and perform easy computations is
            	  introduced. The model cards can be stolen and/or cloned
            	  by the spy. The kernel of their built-in algorithm works
            	  correctly, so they spy cannot acquire unlimited knowledge
            	  from their use. However, their functional interface is
            	  unreliable, so they send correct outputs in an
            	  unspecified order. The provably secure protocol based on
            	  smart cards designed by Shoup \& Rubin is mechanised.
            	  Some design weaknesses (unknown to the authors' treatment
            	  by Bellare \& Rogaway's approach) are unveiled, while
            	  feasible corrections are suggested and verified.
            	  
            	  We realise that the evidence that a protocol achieves its
            	  goals must be available to the peers. In consequence, we
            	  develop a new a principle of prudent protocol design,
            	  goal availability, which holds of a protocol when
            	  suitable guarantees confirming its goals exist on
            	  assumptions that both peers can verify. Failure to
            	  observe our principle raises the risk of attacks, as is
            	  the case, for example, of the attack on Kerberos IV.},
  number = 	 {UCAM-CL-TR-493}
}

@TechReport{UCAM-CL-TR-494,
  author =	 {Spiteri, Mark David},
  title = 	 {{An architecture for the notification, storage and
         	   retrieval of events}},
  year = 	 2000,
  month = 	 jul,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-494}
}

@TechReport{UCAM-CL-TR-495,
  author =	 {Khorsheed, Mohammad S.M.},
  title = 	 {{Automatic recognition of words in Arabic manuscripts}},
  year = 	 2000,
  month = 	 jul,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-495.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The need to transliterate large numbers of historic
            	  Arabic documents into machine-readable form has motivated
            	  new work on offline recognition of Arabic script. Arabic
            	  script presents two challenges: orthography is cursive
            	  and letter shape is context sensitive.
            	  
            	  This dissertation presents two techniques to achieve high
            	  word recognition rates: the segmentation-free technique
            	  and the segmentation-based technique. The
            	  segmentation-free technique treats the word as a whole.
            	  The word image is first transformed into a normalised
            	  polar image. The two-dimensional Fourier transform is
            	  then applied to the polar image. This results in a
            	  Fourier spectrum that is invariant to dilation,
            	  translation, and rotation. The Fourier spectrum is used
            	  to form the word template, or train the word model in the
            	  template-based and the multiple hidden Markov model (HMM)
            	  recognition systems, respectively. The recognition of an
            	  input word image is based on the minimum distance measure
            	  from the word templates and the maximum likelihood
            	  probability for the word models.
            	  
            	  The segmentation-based technique uses a single hidden
            	  Markov model, which is composed of multiple
            	  character-models. The technique implements the analytic
            	  approach in which words are segmented into smaller units,
            	  not necessarily characters. The word skeleton is
            	  decomposed into a number of links in orthographic order,
            	  it is then transferred into a sequence of discrete
            	  symbols using vector quantisation. the training of each
            	  character-model is performed using either: state
            	  assignment in the lexicon-driven configuration or the
            	  Baum-Welch method in the lexicon-free configuration. The
            	  observation sequence of the input word is given to the
            	  hidden Markov model and the Viterbi algorithm is applied
            	  to provide an ordered list of the candidate recognitions.},
  number = 	 {UCAM-CL-TR-495}
}

@TechReport{UCAM-CL-TR-496,
  author =	 {Cattani, Gian Luca and Leifer, James J. and Milner, Robin},
  title = 	 {{Contexts and embeddings for closed shallow action graphs}},
  year = 	 2000,
  month = 	 jul,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-496.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-496}
}

@TechReport{UCAM-CL-TR-497,
  author =	 {Bierman, G.M. and Trigoni, A.},
  title = 	 {{Towards a formal type system for ODMG OQL}},
  year = 	 2000,
  month = 	 sep,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-497}
}

@TechReport{UCAM-CL-TR-498,
  author =	 {Sewell, Peter},
  title = 	 {{Applied $\pi$ -- a brief tutorial}},
  year = 	 2000,
  month = 	 jul,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-498.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This note provides a brief introduction to $\pi$-calculi
            	  and their application to concurrent and distributed
            	  programming. Chapter 1 introduces a simple $\pi$-calculus
            	  and discusses the choice of primitives, operational
            	  semantics (in terms of reductions and of indexed early
            	  labelled transitions), operational equivalences,
            	  Pict-style programming and typing. Chapter 2 goes on to
            	  discuss the application of these ideas to distributed
            	  systems, looking informally at the design of distributed
            	  $\pi$-calculi with grouping and interaction primitives.
            	  Chapter 3 returns to typing, giving precise definitions
            	  for a simple type system and soundness results for the
            	  labelled transition semantics. Finally, Chapters 4 and 5
            	  provide a model development of the metatheory, giving
            	  first an outline and then detailed proofs of the results
            	  stated earlier. The note can be read in the partial order
            	  1.(2+3+4.5).},
  number = 	 {UCAM-CL-TR-498}
}

@TechReport{UCAM-CL-TR-499,
  author =	 {Gain, James Edward},
  title = 	 {{Enhancing spatial deformation for virtual sculpting}},
  year = 	 2000,
  month = 	 aug,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-499.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {The task of computer-based free-form shape design is
            	  fraught with practical and conceptual difficulties.
            	  Incorporating elements of traditional clay sculpting has
            	  long been recognised as a means of shielding a user from
            	  the complexities inherent in this form of modelling. The
            	  premise is to deform a mathematically-defined solid in a
            	  fashion that loosely simulates the physical moulding of
            	  an inelastic substance, such as modelling clay or
            	  silicone putty. Virtual sculpting combines this emulation
            	  of clay sculpting with interactive feedback.
            	  
            	  Spatial deformations are a class of powerful modelling
            	  techniques well suited to virtual sculpting. They
            	  indirectly reshape an object by warping the surrounding
            	  space. This is analogous to embedding a flexible shape
            	  within a lump of jelly and then causing distortions by
            	  flexing the jelly. The user controls spatial deformations
            	  by manipulating points, curves or a volumetric
            	  hyperpatch. Directly Manipulated Free-Form Deformation
            	  (DMFFD), in particular, merges the hyperpatch- and
            	  point-based approaches and allows the user to pick and
            	  drag object points directly.
            	  
            	  This thesis embodies four enhancements to the versatility
            	  and validity of spatial deformation:
            	  
            	  1. We enable users to specify deformations by
            	  manipulating the normal vector and tangent plane at a
            	  point. A first derivative frame can be tilted, twisted
            	  and scaled to cause a corresponding distortion in both
            	  the ambient space and inset object. This enhanced control
            	  is accomplished by extending previous work on bivariate
            	  surfaces to trivariate hyperpatches.
            	  
            	  2. We extend DMFFD to enable curve manipulation by
            	  exploiting functional composition and degree reduction.
            	  Although the resulting curve-composed DMFFD introduces
            	  some modest and bounded approximation, it is superior to
            	  previous curve-based schemes in other respects. Our
            	  technique combines all three forms of spatial deformation
            	  (hyperpatch, point and curve), can maintain any desired
            	  degree of derivative continuity, is amenable to the
            	  automatic detection and prevention of self-intersection,
            	  and achieves interactive update rates over the entire
            	  deformation cycle.
            	  
            	  3. The approximation quality of a polygon-mesh object
            	  frequently degrades under spatial deformation to become
            	  either oversaturated or undersaturated with polygons. We
            	  have devised an efficient adaptive mesh refinement and
            	  decimation scheme. Our novel contributions include:
            	  incorporating fully symmetrical decimation, reducing the
            	  computation cost of the refinement/decimation trigger,
            	  catering for boundary and crease edges, and dealing with
            	  sampling problems.
            	  
            	  4. The potential self-intersection of an object is a
            	  serious weakness in spatial deformation. We have
            	  developed a variant of DMFFD which guards against
            	  self-intersection by subdividing manipulations into
            	  injective (one-to-one) mappings. This depends on three
            	  novel contributions: analytic conditions for identifying
            	  self-intersection, and two injectivity tests (one exact
            	  but computationally costly and the other approximate but
            	  efficient).},
  number = 	 {UCAM-CL-TR-499}
}

@TechReport{UCAM-CL-TR-500,
  author =	 {Yan, Jianxin and Blackwell, Alan and Anderson, Ross and
          	  Grant, Alasdair},
  title = 	 {{The memorability and security of passwords -- some
         	   empirical results}},
  year = 	 2000,
  month = 	 sep,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-500.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {There are many things that are `well known' about
            	  passwords, such as that uers can't remember strong
            	  passwords and that the passwords they can remember are
            	  easy to guess. However, there seems to be a distinct lack
            	  of research on the subject that would pass muster by the
            	  standards of applied psychology.
            	  
            	  Here we report a controlled trial in which, of four
            	  sample groups of about 100 first-year students, three
            	  were recruited to a formal experiment and of these two
            	  were given specific advice about password selection. The
            	  incidence of weak passwords was determined by cracking
            	  the password file, and the number of password resets was
            	  measured from system logs. We observed a number of
            	  phenomena which run counter to the established wisdom.
            	  For example, passwords based on mnemonic phrases are just
            	  as hard to crack as random passwords yet just as easy to
            	  remember as naive user selections.},
  number = 	 {UCAM-CL-TR-500}
}

@TechReport{UCAM-CL-TR-501,
  author =	 {Ingram, David},
  title = 	 {{Integrated quality of service management}},
  year = 	 2000,
  month = 	 sep,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-501}
}

@TechReport{UCAM-CL-TR-502,
  author =	 {Rasmussen, Thomas Marthedal},
  title = 	 {{Formalizing basic number theory}},
  year = 	 2000,
  month = 	 sep,
  institution =  {University of Cambridge, Computer Laboratory},
  address =	 {15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom,
          	  phone +44 1223 763500},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-502}
}

@TechReport{UCAM-CL-TR-503,
  author =	 {Mycroft, Alan and Sharp, Richard},
  title = 	 {{Hardware/software co-design using functional languages}},
  year = 	 2000,
  month = 	 sep,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-503.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {In previous work we have developed and prototyped a
            	  silicon compiler which translates a functional language
            	  (SAFL) into hardware. Here we present a SAFL-level
            	  program transformation which: (i) partitions a
            	  specification into hardware and software parts and (ii)
            	  generates a specialised architecture to execute the
            	  software part. The architecture consists of a number of
            	  interconnected heterogeneous processors. Our method
            	  allows a large design space to be explored by
            	  systematically transforming a single SAFL specification
            	  to investigate different points on the area-time
            	  spectrum.},
  number = 	 {UCAM-CL-TR-503}
}

@TechReport{UCAM-CL-TR-504,
  author =	 {Kwong, Oi Yee},
  title = 	 {{Word sense selection in texts: an integrated model}},
  year = 	 2000,
  month = 	 sep,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-504.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Early systems for word sense disambiguation (WSD) often
            	  depended on individual tailor-made lexical resources,
            	  hand-coded with as much lexical information as needed,
            	  but of severely limited vocabulary size. Recent studies
            	  tend to extract lexical information from a variety of
            	  existing resources (e.g. machine-readable dictionaries,
            	  corpora) for broad coverage. However, this raises the
            	  issue of how to combine the information from different
            	  resources.
            	  
            	  Thus while different types of resource could make
            	  different contribution to WSD, studies to date have not
            	  shown what contribution they make, how they should be
            	  combined, and whether they are equally relevant to all
            	  words to be disambiguated. This thesis proposes an
            	  Integrated Model as a framework to study the
            	  inter-relatedness of three major parameters in WSD:
            	  Lexical Resource, Contextual Information, and Nature of
            	  Target Words. We argue that it is their interaction which
            	  shapes the effectiveness of any WSD system.
            	  
            	  A generalised, structurally-based sense-mapping algorithm
            	  was designed to combine various types of lexical
            	  resource. This enables information from these resources
            	  to be used simultaneously and compatibly, while
            	  respecting their distinctive structures. In studying the
            	  effect of context on WSD, different semantic relations
            	  available from the combined resources were used, and a
            	  recursive filtering algorithm was designed to overcome
            	  combinatorial explosion. We then investigated, from two
            	  directions, how the target words themselves could affect
            	  the usefulness of different types of knowledge. In
            	  particular, we modelled WSD with the cloze test format,
            	  i.e. as texts with blanks and all senses for one specific
            	  word as alternative choices for filling the blank.
            	  
            	  A full-scale combination of WordNet and Roget's Thesaurus
            	  was done, linking more than 30,000 senses. Using these
            	  two resources in combination, a range of disambiguation
            	  tests was done on more than 60,000 noun instances from
            	  corpus texts of different types, and 60 blanks from real
            	  cloze texts. Results show that combining resources is
            	  useful for enriching lexical information, and hence
            	  making WSD more effective though not completely. Also,
            	  different target words make different demand on
            	  contextual information, and this interaction is closely
            	  related to text types. Future work is suggested for
            	  expanding the analysis on target nature and making the
            	  combination of disambiguation evidence sensitive to the
            	  requirements of the word being disambiguated.},
  number = 	 {UCAM-CL-TR-504}
}

@TechReport{UCAM-CL-TR-505,
  author =	 {Cattani, Gian Luca and Sewell, Peter},
  title = 	 {{Models for name-passing processes: interleaving and causal}},
  year = 	 2000,
  month = 	 sep,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-505.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {We study syntax-free models for name-passing processes.
            	  For interleaving semantics, we identify the indexing
            	  structure required of an early labelled transition system
            	  to support the usual $\pi$-calculus operations, defining
            	  Indexed Labelled Transition Systems. For noninterleaving
            	  causal semantics we define Indexed Labelled Asynchronous
            	  Transition Systems, smoothly generalizing both our
            	  interleaving model and the standard Asynchronous
            	  Transition Systems model for CCS-like calculi. In each
            	  case we relate a denotational semantics to an operational
            	  view, for bisimulation and causal bisimulation
            	  respectively. We establish completeness properties of,
            	  and adjunctions between, categories of the two models.
            	  Alternative indexing structures and possible applications
            	  are also discussed. These are first steps towards a
            	  uniform understanding of the semantics and operations of
            	  name-passing calculi.},
  number = 	 {UCAM-CL-TR-505}
}

@TechReport{UCAM-CL-TR-506,
  author =	 {Sewell, Peter},
  title = 	 {{Modules, abstract types, and distributed versioning}},
  year = 	 2000,
  month = 	 sep,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-506.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {In a wide-area distributed system it is often
            	  impractical to synchronise software updates, so one must
            	  deal with many coexisting versions. We study static
            	  typing support for modular wide-area programming,
            	  modelling separate compilation/linking and execution of
            	  programs that interact along typed channels. Interaction
            	  may involve communication of values of abstract types; we
            	  provide the developer with fine-grain versioning control
            	  of these types to support interoperation of old and new
            	  code. The system makes use of a second-class module
            	  system with singleton kinds; we give a novel operational
            	  semantics for separate compilation/linking and execution
            	  and prove soundness.},
  number = 	 {UCAM-CL-TR-506}
}

@TechReport{UCAM-CL-TR-507,
  author =	 {Paulson, Lawrence},
  title = 	 {{Mechanizing a theory of program composition for UNITY}},
  year = 	 2000,
  month = 	 nov,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-507.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Compositional reasoning must be better understood if
            	  non-trivial concurrent programs are to be verified.
            	  Chandy and Sanders [2000] have proposed a new approach to
            	  reasoning about composition, which Charpentier and Chandy
            	  [1999] have illustrated by developing a large example in
            	  the UNITY formalism. The present paper describes
            	  extensive experiments on mechanizing the compositionality
            	  theory and the example, using the proof tool Isabelle.
            	  Broader issues are discussed, in particular, the
            	  formalization of program states. The usual representation
            	  based upon maps from variables to values is contrasted
            	  with the alternatives, such as a signature of typed
            	  variables. Properties need to be transferred from one
            	  program component's signature to the common signature of
            	  the system. Safety properties can be so transferred, but
            	  progress properties cannot be. Using polymorphism, this
            	  problem can be circumvented by making signatures
            	  sufficiently flexible. Finally the proof of the example
            	  itself is outlined.},
  number = 	 {UCAM-CL-TR-507}
}

@TechReport{UCAM-CL-TR-508,
  author =	 {Leifer, James and Milner, Robin},
  title = 	 {{Shallow linear action graphs and their embeddings}},
  year = 	 2000,
  month = 	 oct,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-508.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-508}
}

@TechReport{UCAM-CL-TR-509,
  author =	 {Basalaj, Wojciech},
  title = 	 {{Proximity visualisation of abstract data}},
  year = 	 2001,
  month = 	 jan,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-509.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Data visualisation is an established technique for
            	  exploration, analysis and presentation of data. A
            	  graphical presentation is generated from the data
            	  content, and viewed by an observer, engaging vision --
            	  the human sense with the greatest bandwidth, and the
            	  ability to recognise patterns subconciously. For
            	  instance, a correlation present between two variables can
            	  be elucidated with a scatter plot. An effective
            	  visualisation can be difficult to achieve for an abstract
            	  collection of objects, e.g. a database table with many
            	  attributes, or a set of multimedia documents, since there
            	  is no immediately obvious way of arranging the objects
            	  based on their content. Thankfully, similarity between
            	  pairs of elements of such a collection can be measured,
            	  and a good overview picture should respect this proximity
            	  information, by positioning similar elements close to one
            	  another, and far from dissimilar objects. The resulting
            	  proximity visualisation is a topology preserving map of
            	  the underlying data collection, and this work
            	  investigates various methods for generating such maps. A
            	  number of algorithms are devised, evaluated
            	  quantitatively by means of statistical inference, and
            	  qualitatively in a case study for each type of data
            	  collection. Other graphical representations for abstract
            	  data are surveyed and compared to proximity
            	  visualisation.
            	  
            	  A standard method for modelling prximity relations is
            	  multidimensional scaling (MDS) analysis. The result is
            	  usually a two- or three-dimensional configuration of
            	  points -- each representing a single element from a
            	  collection., with inter-point distances approximating the
            	  corresponding proximities. The quality of this
            	  approximation can be expressed as a loss function, and
            	  the optimal arrangement can be found by minimising it
            	  numerically -- a procedure known as least-squares metric
            	  MDS. This work presents a number of algorithmic instances
            	  of this problem, using established function optimisation
            	  heuristics: Newton-Raphson, Tabu Search, Genetic
            	  Algorithm, Iterative Majorization, and Stimulated
            	  annealing. Their effectiveness at minimising the loss
            	  function is measured for a representative sample of data
            	  collections, and the relative ranking established. The
            	  popular classical scaling method serves as a benchmark
            	  for this study.
            	  
            	  The computational cost of conventional MDS makes it
            	  unsuitable for visualising a large data collection.
            	  Incremental multidimensional scaling solves this problem
            	  by considering only a carefully chosen subset of all
            	  pairwise proximities. Elements that make up cluster
            	  diameters at a certain level of the single link cluster
            	  hierarchy are identified, and are subject to standard
            	  MDS, in order to establish the overall shape of the
            	  configuration. The remaining elements are positioned
            	  independently of one another with respect to this
            	  skeleton configuration. For very large collections the
            	  skeleton configuration can itself be built up
            	  incrementally. The incremental method is analysed for the
            	  compromise between solution quality and the proportion of
            	  proximities used, and compared to Principal Components
            	  Analysis on a number of large database tables.
            	  
            	  In some applications it is convenient to represent
            	  individual objects by compact icons of fixed size, for
            	  example the use of thumbnails when visualising a set of
            	  images. Because the MDS analysis only takes the position
            	  of icons into account, and not their size, its direct use
            	  for visualisation may lead to partial or complete overlap
            	  of icons. Proximity grid -- an analogue of MDS in a
            	  discrete domain -- is proposed to overcome this
            	  deficiency. Each element of an abstract data collection
            	  is represented within a single cell of the grid, and thus
            	  considerable detail can be shown without overlap. The
            	  proximity relationships are preserved by clustering
            	  similar elements in the grid, and keeping dissimilar ones
            	  apart. Algorithms for generating such an arrangement are
            	  presented and compared in terms of output quality to one
            	  another as well as standard MDS.},
  number = 	 {UCAM-CL-TR-509}
}

@TechReport{UCAM-CL-TR-510,
  author =	 {Mortier, Richard and Isaacs, Rebecca and Fraser, Keir},
  title = 	 {{Switchlets and resource-assured MPLS networks}},
  year = 	 2000,
  month = 	 may,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-510.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {MPLS (Multi-Protocol Label Switching) is a technology
            	  with the potential to support multiple control systems,
            	  each with guaranteed QoS (Quality of Service), on
            	  connectionless best-effort networks. However, it does not
            	  provide all the capabilities required of a multi-service
            	  network. In particular, although resource-assured VPNs
            	  (Virtual Private Networks) can be created, there is no
            	  provision for inter-VPN resource management. Control
            	  flexibility is limited because resources must be pinned
            	  down to be guaranteed, and best-effort flows in different
            	  VPNs compete for the same resources, leading to QoS
            	  crosstalk.
            	  
            	  The contribution of this paper is an implementation on
            	  MPLS of a network control framework that supports
            	  inter-VPN resource management. Using resource partitions
            	  known as switchlets, it allows the creation of multiple
            	  VPNs with guaranteed resource allocations, and maintains
            	  isolation between these VPNs. Devolved control techniques
            	  permit each VPN a customised control system.
            	  
            	  We motivate our work by discussing related efforts and
            	  example scenarios of effective deployment of our system.
            	  The implementation is described and evaluated, and we
            	  address interoperability with external IP control
            	  systems, in addition to interoperability of data across
            	  different layer 2 technologies.},
  number = 	 {UCAM-CL-TR-510}
}

@TechReport{UCAM-CL-TR-511,
  author =	 {Grant, Calum},
  title = 	 {{Software visualization in Prolog}},
  year = 	 1999,
  month = 	 dec,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-511.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Software visualization (SV) uses computer graphics to
            	  communicate the structure and behaviour of complex
            	  software and algorithms. One of the important issues in
            	  this field is how to specify SV, because existing systems
            	  are very cumbersome to specify and implement, which
            	  limits their effectiveness and hinders SV from being
            	  integrated into professional software development tools.
            	  
            	  In this dissertation the visualization process is
            	  decomposed into a series of formal mappings, which
            	  provides a formal foundation, and allows separate aspects
            	  of visualization to be specified independently. The first
            	  mapping specifies the information content of each view.
            	  The second mapping specifies a graphical representation
            	  of the information, and a third mapping specifies the
            	  graphical components that make up the graphical
            	  representation. By combining different mappings,
            	  completely different views can be generated.
            	  
            	  The approach has been implemented in Prolog to provide a
            	  very high level specification language for information
            	  visualization, and a knowledge engineering environment
            	  that allows data queries to tailor the information in a
            	  view. The output is generated by a graphical constraint
            	  solver that assembles the graphical components into a
            	  scene.
            	  
            	  This system provides a framework for SV called Vmax.
            	  Source code and run-time data are analyzed by Prolog to
            	  provide access to information about the program structure
            	  and run-time data for a wide range of highly
            	  interconnected browsable views. Different views and means
            	  of visualization can be selected from menus. An automatic
            	  legend describes each view, and can be interactively
            	  modified to customize how data is presented. A text
            	  window for editing source code is synchronized with the
            	  graphical view. Vmax is a complete Java development
            	  environment and end user SV system.
            	  
            	  Vmax compares favourably to existing SV systems in many
            	  taxonometric criteria, including automation, scope,
            	  information content, graphical output form,
            	  specification, tailorability, navigation, granularity and
            	  elision control. The performance and scalability of the
            	  new approach is very reasonable.
            	  
            	  We conclude that Prolog provides a formal and high level
            	  specification language that is suitable for specifying
            	  all aspects of a SV system.},
  number = 	 {UCAM-CL-TR-511}
}

@TechReport{UCAM-CL-TR-512,
  author =	 {Fox, Anthony},
  title = 	 {{An algebraic framework for modelling and verifying
         	   microprocessors using HOL}},
  year = 	 2001,
  month = 	 mar,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-512.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This report describes an algebraic approach to the
            	  specification and verification of microprocessor designs.
            	  Key results are expressed and verified using the HOL
            	  proof tool. Particular attention is paid to the models of
            	  time and temporal abstraction, culminating in a number of
            	  one-step theorems. This work is then explained with a
            	  small but complete case study, which verifies the
            	  correctness of a datapath with microprogram control.},
  number = 	 {UCAM-CL-TR-512}
}

@TechReport{UCAM-CL-TR-513,
  author =	 {Sakai, Tetsuya and Sp{\"a}rck Jones, Karen},
  title = 	 {{Generic summaries for indexing in information retrieval --
         	   Detailed test results}},
  year = 	 2001,
  month = 	 may,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-513.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This paper examines the use of generic summaries for
            	  indexing in information retrieval. Our main observations
            	  are that:
            	  
            	  -- With or without pseudo-relevance feedback, a summary
            	  index may be as effective as the corresponding fulltext
            	  index for precision-oriented search of highly relevant
            	  documents. But a reasonably sophisticated summarizer,
            	  using a compression ratio of 10--30\%, is desirable for
            	  this purpose.
            	  
            	  -- In pseudo-relevance feedback, using a summary index at
            	  initial search and a fulltext index at final search is
            	  possibly effective for precision-oriented search,
            	  regardless of relevance levels. This strategy is
            	  significantly more effective than the one using the
            	  summary index only and probably more effective than using
            	  summaries as mere term selection filters. For this
            	  strategy, the summary quality is probably not a critical
            	  factor, and a compression ratio of 5--10\% appears best.},
  number = 	 {UCAM-CL-TR-513}
}

@TechReport{UCAM-CL-TR-514,
  author =	 {Unyapoth, Asis},
  title = 	 {{Nomadic $\pi$-calculi: Expressing and verifying
         	   communication infrastructure for mobile computation}},
  year = 	 2001,
  month = 	 jun,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-514.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This thesis addresses the problem of verifying
            	  distributed infrastructure for mobile computation. In
            	  particular, we study language primitives for
            	  communication between mobile agents. They can be
            	  classified into two groups. At a low level there are
            	  ``location dependent'' primitives that require a
            	  programmer to know the current site of a mobile agent in
            	  order to communicate with it. At a high level there are
            	  ``location independent'' primitives that allow
            	  communication with a mobile agent irrespective of any
            	  migrations. Implementation of the high level requires
            	  delicate distributed infrastructure algorithms. In
            	  earlier work of Sewell, Wojciechowski and Pierce, the two
            	  levels were made precise as process calculi, allowing
            	  such algorithms to be expressed as encodings of the high
            	  level into the low level; a distributed programming
            	  language ``Nomadic Pict'' has been built for
            	  experimenting with such encodings.
            	  
            	  This thesis turns to semantics, giving a definition of
            	  the core language (with a type system) and proving
            	  correctness of an example infrastructure. This involves
            	  extending the standard semantics and proof techniques of
            	  process calculi to deal with the new notions of sites and
            	  agents. The techniques adopted include labelled
            	  transition semantics, operational equivalences and
            	  preorders (e.g., expansion and coupled simulation), ``up
            	  to'' equivalences, and uniform receptiveness. We also
            	  develop two novel proof techniques for capturing the
            	  design intuitions regarding mobile agents: we consider
            	  ``translocating'' versions of operational equivalences
            	  that take migration into account, allowing compositional
            	  reasoning; and ``temporary immobility'', which captures
            	  the intuition that while an agent is waiting for a lock
            	  somewhere in the system, it will not migrate.
            	  
            	  The correctness proof of an example infrastructure is
            	  non-trivial. It involves analysing the possible reachable
            	  states of the encoding applied to an arbitrary high-level
            	  source program. We introduce an intermediate language for
            	  factoring out as many `house-keeping' reduction steps as
            	  possible, and focusing on the partially-committed steps.},
  number = 	 {UCAM-CL-TR-514}
}

@TechReport{UCAM-CL-TR-515,
  author =	 {Serjantov, Andrei and Sewell, Peter and Wansbrough, Keith},
  title = 	 {{The UDP calculus: rigorous semantics for real networking}},
  year = 	 2001,
  month = 	 jul,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-515.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  number = 	 {UCAM-CL-TR-515}
}

@TechReport{UCAM-CL-TR-516,
  author =	 {Isaacs, Rebecca},
  title = 	 {{Dynamic provisioning of resource-assured and programmable
         	   virtual private networks}},
  year = 	 2001,
  month = 	 sep,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-516.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {Virtual Private Networks (VPNs) provide dedicated
            	  connectivity to a closed group of users on a shared
            	  network. VPNs have traditionally been deployed for
            	  reasons of economy of scale, but have either been
            	  statically defined, requiring manual configuration, or
            	  else unable to offer any quality of service (QoS)
            	  guarantees.
            	  
            	  This dissertation describes VServ, a service offering
            	  dynamic and resource-assured VPNs that can be acquired
            	  and modified on demand. In VServ, a VPN is both a subset
            	  of physical resources, such as bandwidth and label space,
            	  together with the means to perform fine-grained
            	  management of those resources. This network
            	  programmability, combined with QoS guarantees, enables
            	  the multiservice network -- a single universal network
            	  that can support all types of service and thus be
            	  efficient, cost-effective and flexible.
            	  
            	  VServ is deployed over a network control framework known
            	  as Tempest. The Tempest explicitly distinguishes between
            	  inter- and intra-VPN resource management mechanisms. This
            	  makes the dynamic resource reallocation capabilities of
            	  VServ viable, whilst handling highly dynamic VPNs or a
            	  large number of VPNs. Extensions to the original
            	  implementation of the Tempest to support dynamically
            	  reconfigurable QoS are detailed.
            	  
            	  A key part of a dynamic and responsive VPN service is
            	  fully automated VPN provisioning. A notation for VPN
            	  specification is described, together with mechanisms for
            	  incorporating policies of the service provider and the
            	  current resource availability in the network into the
            	  design process. The search for a suitable VPN topology
            	  can be expressed as a optimisation problem that is not
            	  computationally tractable except for very small networks.
            	  This dissertation describes how the search is made
            	  practical by tailoring it according to the
            	  characteristics of the desired VPN.
            	  
            	  Availability of VServ is addressed with a proposal for
            	  distributed VPN creation. A resource revocation protocol
            	  exploits the dynamic resource management capabilities of
            	  VServ to allow adaptation in the control plane on a
            	  per-VPN basis. Managed resource revocation supports
            	  highly flexible resource allocation and reallocation
            	  policies, allowing VServ to efficiently provision for
            	  short-lived or highly dynamic VPNs.},
  number = 	 {UCAM-CL-TR-516}
}

@TechReport{UCAM-CL-TR-517,
  author =	 {Sp{\"a}rck Jones, Karen and Jourlin, P. and Johnson, S.E.
          	  and Woodland, P.C.},
  title = 	 {{The Cambridge Multimedia Document Retrieval Project:
         	   summary of experiments}},
  year = 	 2001,
  month = 	 jul,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-517.ps.gz},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {This report summarises the experimental work done under
            	  the Multimedia Document Retrieval (MDR) project at
            	  Cambridge from 1997-2000, with selected illustrations.
            	  The focus is primarily on retrieval studies, and on
            	  speech tests directly related to retrieval, not on speech
            	  recognition itself. The report draws on the many and
            	  varied tests done during the project, but also presents a
            	  new series of results designed to compare strategies
            	  across as many different data sets as possible by using
            	  consistent system parameter settings.
            	  
            	  The project tests demonstrate that retrieval from files
            	  of audio news material transcribed using a state of the
            	  art speech recognition system can match the reference
            	  level defined by human transcriptions; and that expansion
            	  techniques, especially when applied to queries, can be
            	  very effective means for improving basic search
            	  performance.},
  number = 	 {UCAM-CL-TR-517}
}

@TechReport{UCAM-CL-TR-518,
  author =	 {Yan, Jeff Jianxin and Wu, Yongdong},
  title = 	 {{An attack on a traitor tracing scheme}},
  year = 	 2001,
  month = 	 jul,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-518.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  issn = 	 {1476-2986},
  abstract = 	 {In Crypto'99, Boneh and Franklin proposed a public key
            	  traitor tracing scheme, which was believed to be able to
            	  catch all traitors while not accusing any innocent use