A Syntactical Approach to Belief Update

摘要

In the Belief Change domain, Katsuno and Mendelzon have proposed a set of postulates that should be satisfied by update operators. In 1989, Forbus semantically defined an update operator that satisfies these postulates. In order to calculate the resulting belief base all models of the relevant belief bases must be known. This paper proposes to use the prime implicants and prime implicates normal forms to represent these bases. Using this representation, a syntactical and computationally cheaper version of Forbus belief update operator is defined and a new minimal distance is proposed. We claim that this minimal distance ensures a better commitment between the minimal change criterion and the belief update definition.