Alex Simpson

I am professor of computer science at the Faculty of Mathematics and Physics, University of Ljubljana, Slovenia. I am also employed at the Institute for Mathematics, Physics and Mechanics, Ljubljana. I previously worked at the Laboratory for Foundations of Computer Science, School of Informatics, University of Edinburgh, where from 2010-2015 I held a personal chair in foundations of computer science.

I am interested in the foundations of mathematics and computer science and in interactions between them.

Contact: Alex dot Simpson at fmf dot uni dash lj dot si

This webpage is under construction.

Talks

Selected recent talks.

• Stochastic Calculus via Stopping Derivatives. Talk at Probability Day, Ljubljana, December 2024. (slides)
• Countable and Dependent Choice and Countably Distributive Toposes. Talk at PSSL 109, Leiden, Novermber 2024. (slides)
• A Tutorial on Sheaf Semantics. Invited tutorial at LICS, July 2024. (slides)
• Three Toposes for Probability and Randomness. Topos Colloquium, June 2024. (slides, video)
• Probabilistic Programming with Coinductive Data. Invited talk at MFPS 2023, June 2023. (slides)
• A Mathematical Theory of True Randomness. Two-part seminar given at UNISA in Pretoria, January 2023. (slides, video)
• Synthetic Probability Theory. Categorical Probability and Statistics 2020. (slides, video)

Papers

Selected recent papers and preprints.

• Stochastic Calculus via Stopping Derivatives. (ArXiV preprint)

• An Imperative Language for Verified Exact Real-Number Computation, with Andrej Bauer and Sewon Park. (ArXiV preprint)

• Equivalence and Conditional Independence in Atomic Sheaf Logic. LICS 2024. (ACM publication, LICS slides, ArXiV preprint)

• Behavioural Equivalence via Modalities for Algebraic Effects, with Niels Voorneveld, ACM TOPLAS 42(1):1-45, 2019. (ACM publication)

• Category-theoretic Structure for Independence and Conditional Independence. MFPS 2017. (ENTCS publication, preprint)

Teaching

Selected lecture courses

• Category Theory. Mathematics PhD course, 2022-23. (Lecture videos, Lecture notes)

• Computability Theory. Mathematics MSc course, 2022-23. (Lecture notes)