Belief Revision with Bounded Treewidth

Abstract

Problems arising from the revision of propositional knowledge bases have been intensively studied for two decades. Many different approaches to revision have thus been suggested, with the ones by Dalal or Satoh being two of the most fundamental ones. As is well known, most computational tasks in this area are intractable. Therefore, in practical applications, one requires sufficient conditions under which revision problems become efficiently solvable. In this paper, we identify such tractable fragments for the reasoning and the enumeration problem exploiting the notion of treewidth. More specifically, we present new algorithms based on dynamic programming for these problems in Dalal´s setting and a tractability proof using Courcelle´s Theorem for Satoh´s approach.