Logic Programs, Well-orderings and Forward Chaining

摘要

We investigate the construction of stable models of general propositional logicprograms. We show that a forward-chaining technique, supplemented by a properly chosen safeguards can be used to construct stable models of logic programs. Moreover, the proposed method has the advantage that if a program has no stable model, the result of the construction is a stable model of a subprogram. Further, in such a case the proposed method isolates the inconsistency of the program, that is it points to the part of the program responsible for the inconsistency. The results of computations are called stable submodels. We prove that every stable model of a program is a stable submodel. We investigate the complexity issues associated with stable submodels.