Published: 15th September 2020
DOI: 10.4204/EPTCS.323
ISSN: 2075-2180


Applied Category Theory 2019
University of Oxford, UK, 15-19 July 2019

Edited by: John Baez and Bob Coecke

John Baez and Bob Coecke
A Complete Language for Faceted Dataflow Programs
Antonin Delpeuch
Reflecting Algebraically Compact Functors
Vladimir Zamdzhiev
Autonomization of Monoidal Categories
Antonin Delpeuch
Tracelets and Tracelet Analysis Of Compositional Rewriting Systems
Nicolas Behr
Modeling Hierarchical System with Operads
Spencer Breiner, Blake Pollard, Eswaran Subrahmanian and Olivier Marie-Rose
Functorial Question Answering
Giovanni de Felice, Konstantinos Meichanetzidis and Alexis Toumi
Compositional Game Theory with Mixed Strategies: Probabilistic Open Games Using a Distributive Law
Neil Ghani, Clemens Kupke, Alasdair Lambert and Fredrik Nordvall Forsberg
Enriched Lawvere Theories for Operational Semantics
John C. Baez and Christian Williams
Interfacing biology, category theory and mathematical statistics
Dominique Pastor, Erwan Beurier, Andrée Ehresmann and Roger Waldeck
Compositional Models for Power Systems
John S. Nolan, Blake S. Pollard, Spencer Breiner, Dhananjay Anand and Eswaran Subrahmanian
Topos Semantics for a Higher-Order Temporal Logic of Actions
Philip Johnson-Freyd, Jon Aytac and Geoffrey Hulette
A Compositional Framework for Scientific Model Augmentation
Micah Halter, Christine Herlihy and James Fairbanks
Internal lenses as functors and cofunctors
Bryce Clarke
String Diagrams for Regular Logic (Extended Abstract)
Brendan Fong and David Spivak
Learning Functors using Gradient Descent
Bruno Gavranović
idris-ct: A Library to do Category Theory in Idris
Fabrizio Genovese, Alex Gryzlov, Jelle Herold, Andre Knispel, Marco Perone, Erik Post and André Videla


This volume contains the proceedings of Applied Category Theory 2019, which was held July 15-19 2019, at the Department of Computer Science of Oxford University. This conference had 70 submitted papers and was attended by some 150 participants.

Applied category theory is a topic of interest for a growing community of researchers, interested in studying systems of all sorts using category-theoretic tools. These systems are found in the natural sciences and social sciences, as well as in computer science, linguistics, and engineering. The background and experience of our members is as varied as the systems being studied. The goal of the ACT2019 Conference was to bring the majority of researchers in the field together and provide a platform for exposing the progress in the area. Both original research papers as well as extended abstracts of work submitted/accepted/published elsewhere were considered. All papers were carefully refereed, and the bar for acceptance was set high.

The ACT conference series is run by the same group of academics who manage the new diamond open access journal Compositionality. It therefore made sense to publish in the diamond open access proceedings journal EPTCS, which is also run by academia. In the ACT community we feel very strongly about this issue.

There also was an adjoint school, to help grow this community by pairing ambitious young researchers together with established researchers in order to work on questions, problems, and conjectures in applied category theory. Many of the groups at the school resulted in publications.

Rather than having invited speakers in the usual sense, invited talks were selected from the submitted papers, giving a chance to young researchers having produced outstanding work to take the central stage, which also helps their careers.

The program committee, keynote speakers, and program itself are available at the ACT 2019 website.

We look forward to seeing all of you at the next ACT conferences.

The PC Chairs,
John Baez (UC Riverside) and Bob Coecke (University of Oxford).