The Abductive Event Calculus as a general framework for temporal databases

Abstract

In earlier work, we have shown that the formalism of abductive logic programs with FOL integrity constraints provides, under a completion semantics, the same declarative expressivity for representing incomplete information as full first order logic. We have shown how the combination of this formalism with a variant of the Event Calculus of Kowalski and Sergot results in a correct and very expressive framework for temporal reasoning and representation. In this paper we demonstrate how this Abductive Event Calculus formalism provides a general frame-work for the representation and use of temporal databases. On the declarative level, it is particularly convenient for the representation of incomplete knowledge. Complementary, on the procedural level, we are able to provide a number of simple algorithms using abduction and deduction to test the consistency of the base, answer queries, update the database, handle complex formulas and resolve inconsistency. Furthermore, the use of the database for general temporal problem solving is possible using the known Event Calculus and Logic Programming methods. In particular we show how planning is possible in this kind of temporal database.