December 13, 2016, 2pm, amphitheatre S25, faculty of science


Belief change is about finding appropriate ways to evolve an agent’s beliefs when confronted with new pieces of information. In most works on belief revision, the set of beliefs of an agent is composed of beliefs about the environment (the world) and is represented by a set of formulas of classical logic. In many applications, an agent is not alone in the environment, but sharing with other agents, which also have beliefs. Thus beliefs about the beliefs of other agents are an important piece of information for the agent in order to be able to make the best decisions and perform the best actions. The use of beliefs about the beliefs of other agents is, for exampel, crucial in game theory.

In this thesis, we first study the operators of propositional contraction corresponding to the revision operators proposed by Katsuno and Mendelzon. Then, we study a connection between epistemic logics and belief change theory, close to the AGM approach. We are interested in the use of operators that modify agent beliefs in standard KD45n models. This task is more complicated than in the standard AGM framework because, in a multi-agent context, new information can take different forms. For example, each new information can be observed/transmitted/available to all agents or only some of them.


  • Andreas Herzig - Directeur de recherches CNRS, Université Paul Sabatier - Rapporteur
  • Odile Papini - Professeur des universités, Aix-Marseille Université - Rapporteur
  • François Schwarzentruber - Maître de conférences, ENS Rennes - Examinateur
  • Sébastien Konieczny - Directeur de recherches CNRS, Université d’Artois - Co-directeur
  • Tiago de Lima - Maître de conférences, Université d’Artois - Co-encadrant
  • Pierre Marquis - Professeur des universités, Université d’Artois - Co-directeur