Pacuit: Dynamic Logics of Evidence Based Beliefs

by Yang Liu

Dynamic Logics of Evidence Based Beliefs
Eric Pacuit (University of Maryland)
4:15 PM, Friday, November 1, 2013
Room 4419, CUNY GC

Abstract. The intuitive notion of evidence has both semantic and syntactic features. In this talk, I introduce and motivate an evidence logic for an  agents faced with possibly contradictory evidence from different sources. The logic is based on a neighborhood semantics, where a neighborhood N indicates that the agent has reason to believe that the true state of the world lies in N. Further notions of relative plausibility between worlds and beliefs based on the ordering are then defined in terms of this evidence structure. The semantics invites a number of natural special cases, depending on how uniform we make the  evidence sets, and how coherent their total structure. I will give an overview of the main axiomatizations for different classes of models and discuss logics that describe the dynamics of changing evidence, and the resulting language extensions. I will also discuss some intriguing connections  with logics of belief revision.

This is joint work with Johan van Benthem and David Fernandez-Duque.