Approximating answer sets of unitary Lifschitz-Woo programs

Abstract

We investigate techniques for approximating answer sets of general logic programs of Lifschitz and Woo, whose rules have single literals as heads. We propose three different methods of approximation and obtain results on the relationship between them. Since general logic programs with single literals as heads are equivalent to revision programs, we obtain results on approximations of justified revisions of databases by revision programs. © Springer-Verlag Berlin Heidelberg 2005.