Nathanaël Fijalkow
I am a computer scientist working on program synthesis, games, and automata.
program synthesis
games
automata
Get in touch nathanael.fijalkow@gmail.com
Research topics
The conception of computer programs is a complicated, costly, and error-prone task. Program synthesis is an ideal where the program is automatically generated from its specification. I am particularly interested in inductive synthesis, where the specification consists of a set of examples.
Representative work in this topic:
Scaling Neural Program Synthesis with Distribution-based Search. Nathanaël Fijalkow and Guillaume Lagarde and Théo Matricon and Kevin E. Ellis and Pierre Ohlmann and Akarsh Potta. AAAI Conference on Artificial Intelligence, AAAI. 2022
Reactive synthesis is the special case of program synthesis where the program takes actions over time in a partially controllable environment. I focus on temporal synthesis, where the specification is given by a logical formula in linear temporal logic (LTL) and its extensions.
Representative work in this topic:
Assume-Guarantee Synthesis for Prompt Linear Temporal Logic. Nathanaël Fijalkow and Bastien Maubert and Aniello Murano and Moshe Y. Vardi. International Joint Conference on Artificial Intelligence, IJCAI. 2020
Games on graphs is at the intersection of several fields: verification (model-checking games such as parity games), logic and model theory (Ehrenfeucht–Fraïssé games), automata theory (emptiness and acceptance games), reinforcement learning (Markov decision processes), and optimisation (mean payoff and discounted games).
Representative work in this topic:
The Theory of Universal Graphs for Infinite Duration Games. Thomas Colcombet and Nathanaël Fijalkow and Pawel Gawrychowski and Pierre Ohlmann. Logical Methods in Computer Science, LMCS. Logical Methods in Computer Science. 2022
Markovian models are stochastic models with memoryless dynamics. The distinction with probabilistic automata is that Markovian models such as Markov decision processes are fully observable.
Representative work in this topic:
Controlling a Random Population. Thomas Colcombet and Nathanaël Fijalkow and Pierre Ohlmann. Logical Methods in Computer Science. 2021
A dynamical system follows the evolution of a point through repeated applications of a function; the special case of linear dynamical systems is concerned with linear functions, i.e. multiplication by a matrix. Their algorithmic study is deeply intertwined with deep insights from algebraic number theory and geometry. I am particularly interested in invariants for linear dynamical systems, and in related control problems.
Representative work in this topic:
Complete Semialgebraic Invariant Synthesis for the Kannan-Lipton Orbit Problem. Nathanaël Fijalkow and Pierre Ohlmann and Joël Ouaknine and Amaury Pouly and James Worrell. Theory of Computing Systems. 2019
The study of probabilistic automata, in particular algorithms for learning and controlling them, has many applications, including program verification, natural language processing, modelling of biological systems, and machine learning.
Representative work in this topic:
Undecidability results for probabilistic automata. Nathanaël Fijalkow. SIGLOG News. 2017
News
Tutorial on Machine Learning guided Program Synthesis
I will be giving a half-day tutorial at FM (The International Symposium on Formal Methods) on 6 March 2023
DeepSynth is online and published
DeepSynth is a general-purpose program synthesizer in the programming by example framework: the user provides a few examples as pairs of input and output, DeepSynth finds a program matching the examples.
The software is published in the Journal of Open Source Software and is heavily used in our recent papers for experiments, starting from our AAAI 2022 paper.
Proud of
- Pierre Ohlmann's CSR best paper award and single author student paper at LICS!
- Antonio Casares' single author CSL best student paper (Helena Rasiowa award)!
- Théo Matricon's DeepSynth tool (accepted in JOSS) and our AAAI paper presenting it, invited for Oral Presentation!
- Ritam Raha's Scarlet tool, the fastest LTL learning tool on the market and our TACAS paper presenting it!
Dagstuhl seminar
I am co-organising a Dagstuhl seminar on the Futures of Reactive Synthesis to be held in September 2023
Visiting University of Warsaw
I am visiting the University of Warsaw from September 2022 to June 2023.
Program Committee
I am serving as Program Committee Member for AAAI- 2023, the International Conference on Artificial Intelligence
Research Blog
Collection of research notes, short introductions to recent papers, classical results, open problems
Collaboration
I am a junior researcher at CNRS in LaBRI, Bordeaux (chargé de recherche). I am also a research fellow of The Alan Turing Institute of data science and artificial intelligence in London.
I am looking for a two-year postdoc to work on the G4S project: Games for Synthesis. Please contact me for details!