Maintenance of stratified databases viewed as a belief revision system

Abstract

We study here declarative and dynamic aspects of non-monotonic reasoning in the context of deductive databases. More precisely, we consider here maintenance of a special class of indefinite deductive databases, called stratified databases, introduced in Apt, Blair and Walker [ABW] and Van Gelder [VG] in which recursion “through” negation is disallowed.A stratified database has a natural model associated with it which is selected as its intended meaning. The maintenance problem for these databases is complicated because insertions can lead to deletions and vice versa.To solve this problem we make use of the ideas present in the works of Doyle [D] and de Kleer [dK] on belief revision systems. We offer here a number of solutions which differ in the amount of static and dynamic information used and the form of support introduced. We also discuss the implementation issues and the trade-offs involved.