2026
THEORETICAL COMPUTER SCIENCE
Nicolas Behr
CNRS researcher at IRIF
Institut de Recherche en Informatique Fondamentale · UMR 8243
CNRS · Université Paris Cité · Paris, France
I study the mathematical foundations of rewriting systems, with a focus on categorical structures, compositional reasoning, and stochastic dynamics.
01 / RESEARCH
Structures. Systems. Reasoning.
ICategorical and
Categorical and
algebraic rewriting
IICompositional reasoning about
Compositional reasoning about
systems and their dynamics
IIIExecutable and
Executable and
formalized mathematics
02 / PUBLICATIONS
Papers & preprints
2023
2023
2023
2022
2021
Earlier publications30 entries +
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2006
No publications match your search.
03 / RESEARCH LOGBOOK
Talks & activities
2026
19th International Conference on Graph Transformation (ICGT 2026) (participant), Rennes, France
17th Graph Computation Models International Workshop (GCM 2026) (co-chair), Rennes, France
ANR CoREACT General Meeting (talk), INRIA Center Sophia Antipolis, France
ANR CoREACT Instantiation Calculus WG, LIX, École Polytechnique, France
2025
ANR CoREACT Winter Meeting (organiser; talk), IRIF, France
18th International Conference on Graph Transformation (ICGT 2025) (invited keynote talk), Koblenz, Germany
ANR CoREACT General Meeting (talk), LIX, École Polytechnique, Palaiseau, France
Earlier activities · 2017–202479 entries +
2024
ANR CoREACT Winter Meeting (organiser; talk), IRIF, France
Combinatorics and Arithmetic for Physics: special days workshop (invited talk; slides, video), Institut des Hautes Études Scientifiques (IHÉS), Bures sur Yvette, France
17th International Conference on Graph Transformation (ICGT 2024) (talk), Enschede, The Netherlands
Journées PPS (talk), IRIF, Université Paris Cité, Paris, France
Hypermatrix Workshop 2024 (talk), LPTMC, Sorbonne Université, Paris, France
ANR CoREACT seminar (participant), online
Quo Transformes? workshop (invited talk), University of Pisa, Italy
ANR CoREACT General Meeting (talk), ENS Lyon, France
Higher Segal Spaces and their Applications to Algebraic K-Theory, Hall Algebras, and Combinatorics workshop (invited participant), Banff International Research Station, Calgary, Canada
2023
MDENet France Workshop 2023 (participant), LIP6, Sorbonne Université, Paris, France
ANR CoREACT General Meeting (organiser), IRIF, France
Combinatorics and Arithmetic for Physics: special days workshop (participant), Institut des Hautes Études Scientifiques (IHÉS), Bures sur Yvette, France
14th International Workshop on Graph Computation Models (GCM 2023) (participant), Leicester, UK
Category Theory at Work in Computational Mathematics and Theoretical Informatics meeting (invited talk; slides), Lie-Størmer Center, Bergen, Norway
François Métayer days (participant), IRIF, Université Paris Cité, Paris, France
LHC days 2023, IRIF, Université Paris Cité, Paris, France
Journées PPS (talk; slides), IRIF, Université Paris Cité, Paris, France
IFIP WG1.3 Foundations of System Specification (participant), Paris, France
ANR CoREACT kick-off meeting (organiser; talk), IRIF, Université de Paris, France
2022
Catégories supérieures, polygraphes et homotopie workgroup (talk), IRIF, Université de Paris, France
Virtual Double Categories Workshop (talk; slides, video), online
Combinatorics and Arithmetic for Physics: special days workshop (invited talk; slides, video), Institut des Hautes Études Scientifiques (IHÉS), Bures sur Yvette, France
GDR Renormalisation - Annual Meeting 2022: Hopf Algebras and Applications (talk), Univ. du Littoral Côte d'Opale Calais, France
20th International Conference on Computational Methods in Systems Biology (CMSB 2022) (online participant), Bucharest, Romania
APPLIED CATEGORY THEORY 2022 (online participant), University of Strathclyde, Glasgow, Scotland
15th International Conference on Graph Transformation (ICGT 2022) (co-chair), Nantes, France
13th International Workshop on Graph Computation Models (GCM 2022) (participant), Nantes, France
Topos Institute Colloquium (talk), online
Discrete-event systems and Environmental Sciences meeting (talk), Centre Inria de Paris, France
2021
Combinatorics and Arithmetic for Physics: special days workshop (invited talk; video, slides), Institut des Hautes Études Scientifiques (IHÉS), Bures sur Yvette, France
GReTA international online seminar series (talk; video), online
LACL seminar (talk), Laboratoire d'Algorithmique, Complexité et Logique, Creteil, France
2020
Species and operads in combinatorics and semantics workshop (talk; slides), IRIF, Université de Paris, France
Combinatorics and Arithmetic for Physics: special days workshop (invited talk; video), Institut des Hautes Études Scientifiques (IHÉS), Bures sur Yvette, France
Journées de rentrée PPS (talk), IRIF, Université de Paris, France
CRI Research Collaboratory seminar (talk), Centre de Recherches Interdisciplinaires (CRI), Paris, France
TERMGRAPH 2020: 11th International Workshop on Computing with Terms and Graphs (invited talk), online event
ICGT 2020: 13th International Conference on Graph Transformation (talk), online event
GCM 2020: Eleventh International Workshop on Graph Computation Models (talk), online event
POSTPONED to spring 2021 due to COVID-19 pandemic Colloquium La biologie et la chimie de l'information (invited talk), Collège de France, Paris, France
Computer Science Colloquium (talk), University of Southern Denmark, Odense, Denmark
Informatics Seminar (talk), University of Leicester, UK
2019
LSV Seminar, Laboratoire Spécification et Vérification, ENS Paris-Saclay, Cachan, France
Software Science Departmental seminar (talk), School of Information Technologies, TalTech, Tallinn, Estonia
Combinatorics and Arithmetic for Physics: special days workshop (invited talk), Institut des Hautes Études Scientifiques (IHÉS), Bures sur Yvette, France
FIAS CEF Symposium (talk), Frankfurt Institute for Advanced Studies, Germany
seminar of the Research Group Theoretical Computer Science (talk), Universität Bremen, Germany
PPS seminar (talk), IRIF, Université Paris Diderot, France
15th International Symposium on Orthogonal Polynomials, Special Functions and Applications (OPSFA\'15) (invited talk; slides, video), Research Institute for Symbolic Computation (RISC), Hagenberg, Austria
Applied Category Theory Conference (ACT 2019), University of Oxford (talk; slides, video), Oxford, United Kingdom
Tenth International Workshop on Graph Computation Models (GCM 2019) (talk; slides), Eindhoven University of Technology, Eindhoven, The Netherlands
Journées Aléa 2019, Centre International de Rencontres Mathématiques (CIRM), Marseille, France
Calcul Natural (CANA) seminar (talk), Laboratoire d'Informatique Fondamentale de Marseille (LIF), Marseille, France
2018
Rencontres du GDR Renormalisation, Laboratoire de Mathématiques Blaise Pascal, Clermont-Ferrand, France
Journées PPS (talk), IRIF, Université Paris Diderot, France
Seminar of the Équipe Antique (talk), DI-ENS, Paris, France
Combinatorics and Arithmetic for Physics: special days workshop (invited talk), Institut des Hautes Études Scientifiques (IHÉS), Bures sur Yvette, France
Équipe de travail Analyse et conception de systèmes (talk), IRIF, Université Paris Diderot, France
Emergent Algorithms and Network Dynamics workshop (invited talk; slides), Institut Henri-Poincaré, Paris, France
Séminaires du LPTMC, Sorbonne Université (Paris 6) (talk), France
81st Séminaire Lotharingien de combinatoire (KrattenthalerFest), Strobl, Austria
Computer Science Logic 2018 conference (talk), School of Computer Science of the University of Birmingham, UK
Journée-séminaire de combinatoire, Université Paris 13 (talk), France
Séminaire Systèmes complexes, IRIF, Université Paris Diderot (talk), France
Seminario di ENEA, Centro Ricerche Frascati, Rome (talk), Italy
International Conference on Combinatorics and Physics (Penson71Fest) (invited talk), Polish Academy of Sciences Paris, France
2017
Combinatorics and Arithmetic for Physics: special days workshop (invited talk), Institut des Hautes Études Scientifiques (IHÉS), Bures sur Yvette, France
IRIF Newcomers Day (talk), IRIF, Université Paris Diderot, France
Journée-séminaire de combinatoire (talk), Université Paris 13, France
Séminaires d'Informatique Théorique (talk), DI Université de Rouen, France
04 / RECORDINGS
Recorded talks
Institut des Hautes Etudes Scientifiques (IHES)
Decomposition Spaces in Combinatorics
Watch recording ↗Institut des Hautes Etudes Scientifiques (IHES)Categorification of Rule Algebras
Watch recording ↗Topos InstituteFundamentals of Compositional Rewriting Theory
Watch recording ↗More recordings +
- GReTA seminar #20: "GReTA-ExACT: towards Executable Applied Category Theory" ↗GReTA Seminar
- ACT 2021 - Day 4, Session 1 ↗Applied Category Theory
- (Behr) — Tracelets and Tracelet Analysis Of Compositional Rewriting Systems ↗Jelle Herold
- (Behr) — Tracelets and Tracelet Analysis Of Compositional Rewriting Systems ↗Jelle Herold
05 / BACKGROUNDResearch &
Research &
collaboration
CNRS · IRIF · Université Paris Cité
I am a member of the Preuves, programmes et systèmes group at IRIF.
Together with Andrea Corradini, Reiko Heckel, and Jean Krivine, I organized the GReTA seminar series on graph transformation theory and applications.
My research software includes ReSMT, a Python package exploring rewriting-theoretic operations using the Z3 theorem prover.
Previous positions & education +
Previously, I have been a Short-Term Fellow at CRI Paris in spring and summer of 2020, working on the development of tracelet-analysis algorithms for the biochemistry platform Kappa and for the organo-chemistry platform MØD. I previously held a Marie Skłodowska-Curie Individual Fellowship (2017-2019), working in the field of theoretical computer science at IRIF, Université Paris Diderot. The aim of my project with Jean Krivine (IRIF) consisted in developing extensions of my rule-algebraic framework to restricted variants of rewriting and to the biochemical reaction language Kappa. I am also frequently to be found at the LPTMC of the UPMC/Sorbonne/Paris 06, working with Gérard H.E. Duchamp (Paris 13) and Karol A. Penson (Paris 6) on topics in combinatorics. My previous positions include a Postdoc position with Vincent Danos at ENS Paris and at University of Edinburgh (2014-2017) and a Postdoc position in mathematical physics with Anatoly Konechny at Heriot-Watt University in Edinburgh (2011-2014).
PhD in Mathematical Physics, 2012
Max Planck Institute for Gravitational Physics Golm and Humboldt University Berlin
Diploma in Mathematical Physics, 2008
Max Planck Institute for Gravitational Physics Golm and Humboldt University Berlin