Prioritized Reasoning in Logic Programming

摘要

This work addresses the issue of prioritized reasoning in the context of logic programming. The case of preference conditions involving atoms is considered and a refinement of the comparison method of the ASO semantics is presented. The paper introduces the concept of "choice", as a set of preference rules describing common choice options in different contexts and proposes a new semantics that looks beyond the single preference rules, considering them as a tool for choice representation. More specifically, given a preference rule, its head atoms correspond to the choice options, whereas its body specifies the choice context, I.e. the decisions which have to precede this choice. Finally, a system, called CHOPPER, able to realize both the ASO semantics and its extensions is proposed.