Simple Operational and Denotational Semantics for Prolog with Cut

Abstract We present a research work on the formal study of the Prolog widely-used cut operator. The behaviour of control structures is defined by a reference interpreter described as a rewriting systems (operational semantics). The denotational semantics are shown to be expressible in terms of “stream-generating functions”, which therefore constitute an adequate framework for the study of the properties of Prolog control structures. As an application, we present equivalence rules for Prolog programs, and we discuss the replacement of cut by an if-then-else operator in Prolog dialects.