Answer Sets for Prioritized Logic Programs
Yan Zhang, Norman Foo · The MIT Press eBooks · 1997
Conflict resolution is an important issue in knowledge representation and reasoning. A common idea of solving conflicts in reasoning is to add preferences in the underlying reasoning mechanism. This paper describes extensions of Gelfond and Lifschitz's extended logic programs [5] by adding preference information. We first propose prioritized logic programs (PLPs) in which the preference is expressed statically. An extended answer set semantics is provided for PLPs. We then extend PLPs to dynamic PLPs (DPLPs) in which the preference can be expressed dynamically. The semantics of DPLPs is defined in terms of answer sets of the corresponding PLPs. By illustrating typical examples, we show how conflicts between rules are resolved in PLPs and DPLPs. We also investigate basic properties of PLPs and DPLPs in detail. 1 Introduction Conflict resolution is an important issue in knowledge representation and reasoning. A common idea of solving conflicts in reasoning is to add preferences in the u...