Relevant Minimal Change in Belief Update

Speaker: Jean-Marc Thévenin

Affiliation: Université Toulouse 1 Capitole

Time: Friday 30/11/2012 from 11:30 to 12:30

Venue: Access Grid UWS. Presented from Penrith (Y239), accessible from Parramatta (EB.1.32) and Campbelltown (26.1.50).

Abstract:

The notion of relevance was introduced by Parikh in the belief revision field for handling minimal change. It prevents the loss of beliefs that do not have connections with the epistemic input. But, the problem of minimal change and relevance is still an open issue in belief update.

In this talk, a new framework for handling minimal change and relevance in the context of belief update is introduced. We show that relevant minimal change can be characterized by setting agent's preferences on beliefs where preferences are indexed by subsets of models of the belief set. Each subset represents a prime implicant of the belief set and thus stresses the key propositional symbols for representing the belief set. This allows to highlight the split between the language of the initial belief set and the language of the incoming information . Our framework goes beyond relevance in Parikh's sense and enforces minimal change by first rewriting the Katzuno-Mendelzon postulates for belief update and second by introducing a new relevance postulate.

Biography: Dr Jean-Marc Thévenin received his PhD in Computer Science at Université de Paris 6, Paris in 1989. He is currently a Senior Lecturer at Université Toulouse 1 Capitole. He is a member of the LILaC research group at IRIT and mainly works with Laurent Perrussel and Sylvie Doutre on the research topics, including logical formalization of dialogs, reasoning about action and change, multi-agent frameworks, and formal specification of negotiation and argumentation.