Installed in "contrib" -- JRH 94.03.23

DerLem is a tool, built on top of the standard subgoal package, that
provides:

(1) A layer simulating equational proof style which is frequently used
    in pen-and-paper proofs. This will make equational proofs look more
    natural in HOL.

(2) A layer to administrate forward proving. This is to complement the
    subgoal package, which is basically oriented to backward proving.


Features of DerLem include facility to insert comments, naming of
assumptions, and pretty printing. In addition, these features will
improve documentability of the proofs.

There is an article, 'On the Style of Mechanical Proving' which
accompanies this manual, which should serve as user's manual. There is
also some toy examples to help the user to familiarize hilself with
the package. We suggest the user try the examples.

How to Build/Install
--------------------
No make command is required, simply copy all files in the package to
whatever directory you wish the library to be located.

How to Load
-----------
Simply load `DerLem` from whatever directory you have put the package.
If you have set DerLem directory in the HOL search-path then the
command:

    loadf `DerLem`

will do the job. If you have put DerLem among HOL libraries then of
course:

    load_library `DerLem`

will also do the job.

List of Files:
--------------

README ................................ this file
DL_RefMan.ps .......................... postscript of reference manual
HOLstyle.ps ........................... postscript of user manual
DerLem.ml ............................. ml codes for the DerLem tools
DerLem_ex.ml .......................... some examples


OK, that's all. I hope the package has some use to you.

-Wishnu Prasetya-

%=======================================================================%

DerLem 1.93
by Wishnu Prasetya
Dept. of Computer Science
Utrecht University
the Netherlands

Email: wishnu@cs.ruu.nl
