Embedded Implications and Minimality in ASP
Mauricio Osorio, Magdalena Ortiz · 2004
Disjunctive logic programs under the answer sets semantics play a very significant role in knowledge representation and non monotonic reasoning. As the semantics has been extended to wider classes of programs, it has been observed that implication in the body of rules can be interesting, both for theoretical and practical issues. Here we present an extension of the answer sets semantics to programs with embedded implications in the body of the rules. Since the answer sets of these extended programs are not necessarily minimal, we introduce the notion of rigid programs as a condition that assures the minimality of answer sets for arbitrary theories. We also introduce an extended family of logic programs with restricted use of implication in the body of the rules and address some practical knowledge representation issues through this extension.