Equivalences of Logic Programs

One of the most important relationships between programs (in any programming language) is the equivalence of such programs. This relationship is at the basis of most, if not all, programming methodologies. This paper provides a systematic comparison of the relative strengths of various formulations of equivalence for logic programs. It also introduces the notion of subsumption-equivalence, which is used to give syntactic characterizations of the programs P for which the function TP satisfies some continuity properties.