Third Workshop on String Diagrams in Computation, Logic and Physics (STRINGS 3)

and the

Fifth Symposium on Compositional Structures (SYCO 5)

University of Birmingham, UK
4-6 September 2019

Reimbursements: If you have applied for and were granted travel support please follow the instructions in this document and hand all the documents to Dan Ghica.

Information: All talks (and coffee breaks) will be held in the Watson Building (School of Mathematics) on the main (Edbgbaston) Campus of the University of Birmingham. All lunches will be served in the atrium of the Computer Science building. The campus is most easily accessible via the University train station.


SYCO will take place on Wednesday 4 September and the morning of Thursday 5 September. STRINGS will take place on the afternoon of Thursday 5 September and all day on Friday 6 September.

TimeWednesday 4 SeptemberThursday 5 SeptemberFriday 6 September
09:30Christina Vasilakopoulou, "The dialectical category and related structures" (invited) (slides) (video)Koko Muroya, "Local reasoning for robust observational equivalence" (invited) (slides) (video)
10:30REGISTRATION AND COFFEEJules Hedges, "Bundles, lenses and machine learning" (slides) (video)Dan R. Ghica, "Teaching category theory in primary schools" (video)
11:30Robin Piedeleu, "Diagrammatic methods in concurrency" (invited) (video)Mario Román, Bryce Clarke, Fosco Loregian, Emily Pillmore, Derek Elkins, Bartosz Milewski and Jeremy Gibbons, "Profunctor optics, a categorical update" (slides) (video)Detlef Plump, "Rule-based graph programs" (invited) (slides) (video)
12:00Mario Alvarez-Picallo, "Generalizing Newton's method to change actions"
12:30Peter Guthmann, "The tricategory of formal composites and its strictification" (slides) (video)David Dalrymple, "Dioptics: a common generalization of open games and gradient-based learners" (paper) (slides) (video)Jules Hedges and Jelle Herold, "Foundations of brick diagrams" (slides) (video)
13:00LUNCH (CS Building)LUNCH (CS Building)LUNCH (CS Building)
14:00Noam Zeilberger, "Towards a compositional analysis of higher edge-connectivity in linear λ-terms as 3-valent graphs" (invited) (slides) (video)Mehrnoosh Sadrzadeh, "String diagrams for natural language processing" (invited) (video)Aleks Kissinger, "Optimisation and verification of quantum circuits with string diagrams" (invited) (slides) (video)
15:00Nicolas Blanco, "Models of classical linear logic via bifibrations of polycategories" (slides) (video)Chad Nester, "String diagrams for cartesian restriction categories" (slides) (video)John van der Wetering, "Simulation of quantum circuits by ZX-diagram contraction" (slides) (video)
16:00Yanying Wu and Quanlong Wang, "A categorical compositional distributional modelling for the language of life" (slides) (video)Jean Krivine, "Physical systems, composite explanations and diagrams" (invited) (video)
16:30Malin Altenmüller and Ross Duncan, "A combinatorial presentation of the operad of plane graphs" (slides) (video)
17:00DRINKS RECEPTIONQuanlong Wang, "Completeness of qubit ZX-calculus via elementary operations" (slides) (video)

Best student presentation award

Chad Nester
Chad Nester
University of Edinburgh
String diagrams for cartesian restriction categories
(slides) (video)

Introduction to STRINGS

String diagrams are a powerful tool for reasoning about processes and composition, which are becoming increasingly applied in the formal study of digital circuits, control theory, concurrency, quantum and classical computation, natural language processes, and more. This workshop aims to bring together researchers applying string diagrams in a variety of fields to collaborate and share new insights, tools, and techniques.

Previous instances of this workshop were held in Oxford 2017 and Shonan 2018.

Introduction to SYCO

The Symposium on Compositional Structures is a new interdisciplinary series of meetings aiming to support the growing community of researchers interested in the phenomenon of compositionality, from both applied and abstract perspectives, and in particular where category theory serves as a unifying common language. We welcome submissions from researchers across computer science, mathematics, physics, philosophy, and beyond, with the aim of fostering friendly discussion, disseminating new ideas, and spreading knowledge between fields. Submission is encouraged for both mature research and work in progress, and by both established academics and junior researchers, including students.

Submission is easy, with no format requirements or page restrictions. The meeting does not have proceedings, so work can be submitted even if it has been submitted or published elsewhere. You could submit work-in-progress, or a recently completed paper, or even a PhD or Masters thesis.

While no list of topics could be exhaustive, SYCO welcomes submissions with a compositional focus related to any of the following areas, in particular from the perspective of category theory:

This new series aims to bring together the communities behind many previous successful events which have taken place over the last decade, including Categories, Logic and Physics, Categories, Logic and Physics (Scotland), Higher-Dimensional Rewriting and Applications, String Diagrams in Computational, Logic and Physics, Applied Category Theory, Simons Workshop on Compositionality, the Yorkshire and Midlands Category Theory Seminar, and the Peripatetic Seminar in Sheaves and Logic.

This event follows SYCO 1 in Birmingham, SYCO 2 in Strathclyde, SYCO 3 in Oxford, and SYCO 4 in Orange, California.

Invited speakers

Important dates

All deadlines are 23:59 anywhere-on-earth on the given dates.


If you plan to attend, please register by filling out the following online form:

There is no registration fee.


There are 47 participants, including the following people.

Local information

WARNING: hotel accommodation in Birmingham is already running low for the conference dates. We recommend that you organize your accommodation as soon as possible.

Local organizer. The local organizers are Dan Ghica and Jamie Vicary. Please get in touch directly by email if you have any questions.

Venue. The meeting will take place on the campus of the University of Birmingham. The room will be announced closer to the time of the event.

Accommodation. Book your accommodation as soon as possible, as hotel rooms are already selling out in Birmingham on the dates of the Symposium. If you would like hotel accommodation, we advise you to choose a hotel near Birmingham New Street station, and travel to the conference venue using the quick and regular train service; a standard choice is the Holiday Inn Express. There are also many AirBnB places available in Birmingham; while there isn't much available for the conference dates near the University, there are plenty of places near Five Ways station and Birmingham New Street station, which have direct trains to the conference venue.

Trains. With the University train station within the campus itself, the train is an easy way to get to the symposium. Travel time is 11 minutes from Birmingham New Street, 27 minutes from Birmingham airport, 1 hour 7 minutes from Leicester, 1 hour 14 minutes from Sheffield, 1 hour 17 minutes from Oxford, 1 hour 34 minutes minutes from London, 2 hours 14 minutes from Leeds, 4 hours 40 minutes from Glasgow, and 4 hours 52 minutes from Paris.

Planes. If travelling from far afield, Birmingham airport has flights from all over Europe, and is 27 minutes by train from the conference venue. Birmingham is also conveniently serviced by several other airports: Manchester Airport, Liverpool John Lennon Airport, Bristol Airport, and London Gatwick Airport are about 2 hours by public transport, Heathrow Airport is 2 hours 30 minutes, and Stansted Airport has a direct service to Birmingham New Street that takes 3 hours.

Automobiles. The university has some limited pay-and-display parking (see section "Visitor Parking"), but it is often very busy and it can be hard to find a space. A more reliable option is to park on one of the roads just south of the University which do not have parking restrictions, such as Hubert Road, Tiverton Road or Dawlish Road; these roads are a 10-minute walk to the conference venue.

Taxis. You can book a traditional taxi by phone on 01214278888 or 01217441111. Also, Uber operates in the city.

Internet access. The best way to access the internet at the University of Birmingham is by using the Eduroam service; you can download a configuration tool for your device here. If you do not have access to Eduroam, you can get a guest WiFi password at the registration desk.


Submission is now closed.

Submissions should present research results in sufficient detail to allow them to be properly considered. We encourage the submission of work in progress, as well as mature results. There are no proceedings, so work can be submitted even if it has been previously published, or has been submitted for consideration elsewhere. There is no specific formatting requirement, and no page limit, although for long submissions authors should be aware that reviewers will not be able to read the entire document in detail. Think creatively—you could submit a recent paper, draft notes of a project in progress, or even a recent Masters or PhD thesis.

To indicate the meeting for which you would like your submission to be considered, append "(STRING)" or "(SYCO)" in the title field of the EasyChair submission page. If you would be happy for it to be presented at either meeting, you may append both.

If you have a submission which was deferred from a previous SYCO meeting, it will not automatically be considered for SYCO 5; you still need to submit it again explicitly. Such a submission will be prioritised for inclusion in the SYCO 5 programme. When submitting, append "(DEFERRED FROM SYCO X)" to the title of your paper, replacing "X" with the appropriate meeting number. There is no need to attach any documents.

Travel support

Some travel funding is available to cover travel and subsistence costs, with a priority for students and junior researchers. To apply for this funding, please send an email to Dan Ghica at <> by the deadline Wednesday 21 August, with subject line "STRINGS 3/SYCO 5 funding application", giving a brief summary of your current status, travel costs and funding required.

Programme committee

Steering committees

STRING is managed by Dan R. Ghica, Aleks Kissinger, and Pawel Sobocinski.

SYCO is managed by the following people. If you have a general question about SYCO, or if you want to propose to host a future version, please get in touch with a member of the steering committee.