Joint Tabling of Logic Program Abductions and Updates

ABSTRACT. Abduction in logic programs (abductive logic programs) offers a formalism to declaratively represent and reason about problems in a variety of areas, e.g., in diagnosis, decision making, reasoning about actions, and hypothetical reasoning. On the other hand, the problem of logic program updates allows us to express knowledge changes, be they internal (or self) and external (or world) changes. Abductive logic programs and logic program updates thus naturally coexist in problems or applications that are susceptible to hypothetical reasoning about updates and changes. Taking this as a motivation, in this paper we integrate abductive logic programs and logic program updates by exploiting tabling features in logic programming. The integration is based on and benefits from the two implementation techniques we devised previously, viz., tabled abduction and incremental tabling for query-driven propagation of logic program updates. A prototype of the integrated system is implemented in XSB Prolog.