Nicolas Chappe

I am a post-doctoral researcher at Verimag.

Before that, I was a PhD student in the CASH team at LIP, ENS de Lyon.

You can find my CV here.

Research

My main research interests are compilers and programming languages, both from theoretical and practical points of view.

In the context of my PhD, I developed tools to reason on concurrent programs using monadic interpreters in the Rocq prover, with the distant long-term perspective of extending the Vellvm project to concurrent programs.

The three main contributions of my PhD are as follows:

• I am a major contributor to the Choice Trees Coq library, a coinductive data structure to represent and reason about nondeterministic programs. See its introductory paper (POPL'23).
• I developed a novel notion of bisimulation, intertwined bisimulation, and used it in a Choice Trees setting.
• I used the Choice Trees library to define a semantic model for a concurrent subset of LLVM IR in a CPP'25 paper.

My PhD thesis is available here, and the slides here.

Publications

• Nicolas Chappe, Ludovic Henrio, Yannick Zakowski. Monadic Interpreters for Concurrent Memory Models: Executable semantics of a concurrent subset of LLVM IR.In Proceedings of the 14th ACM SIGPLAN International Conference on Certified Programs and Proofs (CPP '25), 283–298.
• Nicolas Chappe, Paul He, Ludovic Henrio, Yannick Zakowski and Steve Zdancewic. Choice Trees: Representing Nondeterministic, Recursive, and Impure Programs in Coq. Proc. ACM Program. Lang. 7, POPL, Article 61 (January 2023), 31 pages.
• Nicolas Chappe, Ludovic Henrio, Amaury Maillé, Matthieu Moy and Hadrien Renaud. An Optimised Flow for Futures: from Theory to Practice. The Art, Science, and Engineering of Programming, vol. 6, no. 1, 2022, article 3.
• Eddy Caron and Nicolas Chappe. FicWebBoard: A Playful and Collaborative Learning Platform Built for All People and All Programming Languages. 2023 IEEE ASEE Frontiers in Education Conference (FIE), Oct 2023

Drafts

• Draft for an extended version of our POPL'23 paper on Choice Trees, with several new results.

Teaching

In 2021-2022, I wrote a set of exercise sheets for the systems and networking labs of the then-new M2 préparation à l'agrégation of the CS department at ENS de Lyon. You can find them here (in French).

For further information on my teaching activities, see my CV.