Initially, I worked on proof theory in linear logic.
As linear logic can be used for modelling the syntax and the semantics of natural languages, I was induced to take an interest in this topic, but linear logic is a too rigid framework for catching the subtleties of natural languages. Keeping the resource sensitivity of the linear logic, I designed a more flexible framework for modelling the syntax of natural languages: Interaction Grammars.
Currently, I am exploring a new paradigm, Graph Rewriting, for processing the syntax and the semantics of natural languages. This paradigm is very promising. A graph rewriting system, GREW, was developed by Bruno Guillaume and Guillaume Bonfante. I am using GREW for developing different rule systems dedicated to French: a parsing system, a system generating deep syntax from surface syntax and a system generating semantics from deep syntax.
I am also involved with Marie Candito and Bruno Guillaume in the annotation of a French corpus, Sequoia, with two levels of syntactic dependencies, surface dependencies and deep dependencies.