Concurrent constraints in the fusion calculus

Abstract

We use the fusion calculus, a generalization and simplification of the 7r-calculus, to model concurrent constraint programming. In particular we encode three basic variants of the p-calculus, which is a foundational calculus for the concurrent constraint programming language Oz. Using a new reduction-based semantics and weak barbed congruences for the fusion calculus we formally establish an operational correspondence between the p-calculi and their encodings. These barbed congruences are shown to coincide with the hypcrcquivalenccs previously adopted for the fusion calculus.