Abstract: "The paper considers open logic programs originally introduced in [2] as a tool to build an OR-compositional semantics of logic programs. We extend the semantic definitions of [2] in the framework of the general approach to the semantics of logic programs described in [13]. We first d...

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Bibliographische Detailangaben

Format:	Buch
Sprache:	English
Veröffentlicht:	Pisa 1991
Schriftenreihe:	Università degli Studi <Pisa> / Dipartimento di Informatica: Technical report 1991,17
Schlagworte:	Logic programming
Zusammenfassung:	Abstract: "The paper considers open logic programs originally introduced in [2] as a tool to build an OR-compositional semantics of logic programs. We extend the semantic definitions of [2] in the framework of the general approach to the semantics of logic programs described in [13]. We first define an OR-compositional operational semantics O[subscript omega](P) modeling computed answer substitutions. We consider next the semantic domain of [omega]-interpretations, which are sets of clauses with a suitable equivalence relation. The fixpoint semantics F[omega](P) given in [2] is proved equivalent to the operational semantics, by using an intermediate unfolding semantics From the model-theoretic viewpoint, an [omega]-interpretation is mapped onto a set of Herbrand interpretations, thus leading to a definition of [omega]-model based on the classical notion of truth. We show that under a suitable partial order, the glb of a set of [omega]-models of a program P is an [omega]-model of P and is equal to the usual Herbrand model. Moreover, F[subscript omega](P) is a (non-minimal) [omega]-model, equivalent to the model-theoretic semantics defined in [2].
Beschreibung:	25 S.