Graph theoretical structures in logic programs and default theories

Graph Theoretical Structures in Logic Programs and Default Theories

In this paper we present a graph representation of logic programs and default theories. We show that many of the semantics proposed for logic programs can be expressed in terms of notions emerging from graph theory, establishing in this way a link between the fields. Namely the stable models, the partial stable models, and the well-founded semantics correspond respectively to the kernels, semik...

Relating Disjunctive Logic Programs to Default Theories

This paper presents the relationship between disjunctive logic programs and default theories. We rst show that Bidoit and Froidevaux's positivist default theory causes a problem in the presence of disjunctive information in a program. Then we present a correct transformation of disjunctive logic programs into default theories and show a one-to-one correspondence between the stable models of a p...

Logic Programs: Default Logic Theories or Inductive Deenitions?

In his 1975 paper \What is in a link?", Woods pointed out that early approaches in semantic nets were epistemologically ambiguous. Diierent meanings could and had been attributed to the same network. The current paper is a similar enterprise and shows an epistemological ambiguity arising in the context of logic programming. Many diierent logic programming formalisms and semantics have been prop...

Strong Equivalence for Logic Programs and Default Theories (Made Easy)

Construction of Belief Sets for Logic Programs and Default Theories

We present a uniied approach to the construction of belief sets for logic programs with the classical connective of negation, disjunctive logic programs, and what we call arbitrary logic programs that contain an arbitrary formula in the head and arbitrary formulas in the premises of a program rule. The approach is based on a nondetermin-istic iterative operator constrained by a dynamic preferen...