Dario Stein

Computer Scientist · Mathematician · dario-stein@outlook.com

I am a theoretical computer scientist interested in Probability Theory, the Semantics of Programming Languages and Category Theory. These disciplines come together in the exciting new fields of probabilistic programming and categorical probability, which are promising approaches for building verifiable and explainable AI. I am also interested in causal inference, interactive theorem proving, type theory, functional programming with effects, string diagrams, quantum computation and universal algebra.


Curriculum Vitae

Here is a short overview of my CV. You can find my full CV here.

Researcher in Theoretical Computer Science

iHub, RU Nijmegen

Postdoctoral Researcher with Bart Jacobs

December 2021 - December 2025

DPhil in Computer Science

University of Oxford

Supervisor: Sam Staton

Thesis: Structural Foundations for Probabilistic Programming Languages

October 2021

MASt in Pure Mathematics

Part III of the Mathematical Tripos, University of Cambridge

Assessor: Peter Johnstone

Essay topic: Locally presentable and accessible categories

July 2017

BSc in Mathematics

University of Hamburg

Supervisor: Bernd Siebert

Thesis: On branched coverings of P¹ and orbits of the Hurwitz action

July 2014

Talks

Talks
  • Jan 2026, Keynote "A Welcome to Causal Probabilistic Programming", LAFI Workshop, Rennes
  • Nov 2025, "Categorical Approaches to Probability", MPI-SP Bochum
  • Nov 2025, "Categories of Relations which Compose Independently", University of Ljubljana
  • Sep 2025, "Categories of Relations which Compose Independently", Aarhus University
  • May 2025, Topos Institute Colloquium
  • May 2025, "Independence Structures and Dagger Categories of Relations", DutchCATS, University of Utrecht
  • Mar 2025, "Interventions and Counterfactuals for the Working Programmer", Logic and Semantics Seminar, University of Cambridge
  • Sep 2024, ItaCa Fest 2024, Online
  • Jul 2024, SWS Seminar, Radboud University Nijmegen
  • Jun 2024, DutchCATS 2024, Leiden
  • Apr 2024, FoSSaCS 2024, Luxembourg
  • Nov 2023, DutchCATS 2023, Radboud University Nijmegen
  • Jul 2023, ACT 2023, University of Maryland
  • Jun 2023, MFPS 2023, Bloomington, Indiana
  • Jun 2023, CALCO 2023, Bloomington, Indiana (Best Presentation Award)
  • May 2023, Southern Logic Seminar, UCL
  • Feb 2023, CSL 2023, University of Warsaw
  • Jan 2023, Inn'formal Probability Seminar, Universität Innsbruck
  • Aug 2022, Introduction to Probabilistic Programming, SWS Seminar, Radboud University Nijmegen
  • Jul 2022, "A Hypergraph Category for Exact Gaussian Inference", Applied Category Theory 22 (slides, video), Strathclyde
  • Jul 2022, Tutorial on Probabilistic Programming, iHub, Radboud University Nijmegen
  • Jul 2021, Mathematical Foundations Seminar, Bath
  • Jul 2021, VeriProP 2021
  • Jun 2021, LICS 2021
  • Jan 2021, Oxford Quantum Group Workshop
  • Jan 2021, POPL 2021 (View on Clowdr)
  • Jan 2021, LAFI. Slides
  • Oct 2020, ProbProg workshop, MIT/Online
  • Feb 2020, PIHOC workshop, IRIF, Paris. Slides
  • Jan 2020, LAFI workshop, POPL, New Orleans. Slides
  • 2019, Junior Semantics Seminar x 2, Oxford
  • Jul 2018, ICALP 2018, Prague
  • 2018, Quantum Lunch, Quantum Group, Oxford

Publications

Conference Papers


Journal Articles

DPhil Thesis


Preprints

Prospective Students

Are you a motivated student looking for a project? Write me an email! I am keen on (co)supervising BSc and MSc Projects as well as Research Internships. Below are some example topics that interest me:

BSc Topics
  • Presentations of Convex Spaces
    Convex spaces are algebraic structures similar to vector spaces, which model convex subsets of Euclidean space. They are useful in the study of probabilistic computation. You will investigate some algebraic questions about convex spaces, related to free algebras and presentations.

  • Reflections into Free Algebras
    Free algebras are the basic building blocks of algebraic structures. You will investigate algebras which can be approximated by free algebras in a certain sense, or prove why such an approximation is impossible.

  • Uniqueness of Retrodiction:
    You will study the monoid of endo-relations on a set X, and try to classify the automorphisms of this monoid.

MSc Topics
  • Nominal Sets and Probability
    Nominal sets are a mathematical formalism for dealing with names such as variable names or memory locations in programming languages. It doesn't matter what these names are -- we only care whether two names are equal or not. For example, variables bindings are often considered up to α-equivalence. In this project, you'll investigate various formal similarities between fresh name generation (choosing a new variable name, or allocating a memory location), and probability.

  • Random Variables and Isometry-Sets
    How can the notion of random variables be formalized in category theory? This project will involve sheaves over categories of sample spaces. A concrete model are Iso-Sets, a novel continuous generalization of nominal sets using isometries of Euclidean space

  • Type Theory for Equivariance
    Group actions are a fundamental language for describing mathematical structures with symmetries. How would a type theory look where everything that typechecks is automatically equivariant?

  • Formalization of Categorical Probability
    There are many challenges involving monoidal category theory and string diagrams in proof assistants such as Lean or Rocq


Supervision


  • PhD Students
    Márk Széles (cosupervision with Bart Jacobs), 2023 - present

  • Bachelor Students
    Gideon de Hoop (daily supervisor), Sep 2024-Jan 2025

  • MFOCS Seminar
    Tjitske Koster (2022), Sergio Dominguez Cabrera (2023), Dick Blankvoort (2023), Bas van der Linden (2024)


Teaching


  • Spring 25, Lecturer for Category Theory and Coalgebra, Radboud University Nijmegen
  • Spring 24, Lecturer for Category Theory and Coalgebra, Radboud University Nijmegen
  • Winter 2023-24, MFoCS Seminar at Radboud University Nijmegen
  • Spring 23, Lecturer for Category Theory and Coalgebra, Radboud University Nijmegen
  • Winter 2022-23, MFoCS Seminar at Radboud University Nijmegen
  • Spring 2022, Tutor for Category Theory and Coalgebra at Radboud University Nijmegen
  • Michaelmas 2020, Tutor for Categories, Proofs and Processes at University of Oxford
  • Hilary 2020, Tutor for Quantum Information at University of Oxford
  • Michaelmas 2019, Tutor for Principles of Programming Languages at University of Oxford.
  • Hilary 2019, Tutor for Probability and Computing at University of Oxford.

Service

Program Committees


Committee Member for 14th ACM SIGPLAN Workshop on Higher‑Order Programming with Effects (HOPE 2026)
Committee Member for 41st Conference on Mathematical Foundations of Programming Semantics (MFPS 2025)
Committee Member for Applied Category Theory (ACT 2024)
Committee Member for Applied Category Theory (ACT 2023)
Committee Member for Languages for Inference (LAFI 2023)
Committee Member for ProbProg 2021

Reviewer


Logical Methods in Computer Science (2026)
29th International Conference on Foundations of Software Science and Computation Structures (FoSSaCS 2026)
34th EACSL Annual Conference on Computer Science Logic (CSL 2026)
53rd ACM SIGPLAN Symposium on Principles of Programming Languages (POPL 2026)
Compositionality (2025)
Proceedings of the Royal Society (2025)
Annals of Pure and Applied Logic (2024)
Compositionality (2024)
39th Annual Symposium on Logic in Computer Science (LICS 2024)
27th International Conference on Foundations of Software Science and Computation Structures (FoSSaCS 2024)
32nd European Symposium on Programming (ESOP 2023)
26th International Conference on Foundations of Software Science and Computation Structures (FoSSaCS 2023)
47th International Symposium on Mathematical Foundations of Computer Science (MFCS 2022)
37th Annual Symposium on Logic in Computer Science (LICS 2022)
36th Annual Symposium on Logic in Computer Science (LICS 2021)
International Conference on Formal Structures for Computation and Deduction (FSCD)
Mathematical Structures in Computer Science (MSCS)

Student Volunteer


47th ACM SIGPLAN Symposium on Principles of Programming Languages (POPL 2020)
Federated Logic Conference (FLOC 2018)

Contact Information

Email: dario-stein@outlook.com