A simple modal logic for belief revision

Giacomo Bonanno

pp. 193-228

in: Knowledge, rationality & action, Synthese 147 (2), 2005.

Abstract

We propose a modal logic based on three operators, representing intial beliefs, information and revised beliefs. Three simple axioms are used to provide a sound and complete axiomatization of the qualitative part of Bayes’ rule. Some theorems of this logic are derived concerning the interaction between current beliefs and future beliefs. Information flows and iterated revision are also discussed.