A Syntactical Approach to Revision

The aim of this article is to revisit Dalal’s operator for belief revision. Dalal has proposed a technique for revising belief bases based on the minimization of a distance between interpretations. The result is a concrete operator that can be considered either from a semantical point of view (distance between interpretations) or from a syntactical point of view (number of atoms that have their truth values changed). Dalal has shown that the so-called Alchourrón, Gärdenfors and Makinson (AGM) postulates are satisfied by its operator. The AGM postulates constrain the revision process so that minimal changes occur in the belief set. In this article, our contribution is twofold: first, we improve Dalal’s algorithm by avoiding multiple satisfiability checking, which are NP-complete tasks. Our algorithm requires only one NP-stage if beliefs are expressed in a specific syntax, namely the prime implicates and prime implicants. Second, we propose a new distance based on the number o...

• Type: Conference
• Year: 2004
• Where: ECAI
• Authors: Guilherme Bittencourt, Laurent Perrussel, Jerusa Marchi
• Keywords: Artificial Intelligence, Belief Revision, Dalal’s Operator, ECAI 2004, Minimal Changes