Alternative proposals for implementing Prolog concurrently and implications regarding their respective microarchitectures

Prolog has become a subject of much discussion of late. It has been suggested as the logical language for programming expert systems. A parallel variant is said to be the language of the Japanese 5th Generation Project. In this paper the standard Prolog language is defined and shown to be a restriction of Logic Programming. Several alternative schemes, which have been proposed for improving the performance of Prolog, are examined. Some schemes change the semantics of the language; these effects are discussed. All schemes have implications on the microarchitecture of the implementing engine; these implications are studied.