RIS ID
11279
Abstract
Most existing formalizations treat belief change as a single step process, and ignore several problems that become important when a theory, or belief state, is revised over several steps. This paper identifies these problems, and argues for the need to retain all of the multiple possible outcomes of a belief change step, and for a framework in which the effects of a belief change step persist as long as is consistently possible. To demonstrate that such a formalization is indeed possible, we develop a framework which uses the language of PJ-default logic to represent a belief state, and which enables the effects of a belief change step to presist by propagating belief constraints. Belief change in this framework maps one belief state to another, where each belief state is a collection of theories given by the set of extensions of the PJ-default theory representing that belief state. Belief constraints do not need to be separately recorded; they are encoded as clearly identifiable components of a PJ-default theory. The framework meets the requirements for iterated belief change that we identify and satisfies most of the AGM postulates as well.
Publication Details
This article was originally published as Ghose, AK, Hadjinian, PO, Sattar, A, You, J and Goebel, R, Iterated belief change, Computational Intelligence, 2004, 20(1), 37-55. The definitive version is available at www.blackwell-synergy.com. Copyright 2004 Blackwell Publishing.