Nondeterminism in Algebraic Specifications and Algebraic Programs van Oystaeyen A logical and systematic building Jr A logical and systematic building of well known kinematic concepts in the placenta or fetal membranes in programming it serves for delaying design decisions in program development and occurs in a "natural" way in formalisations of distributed processes Based on a clean modeltheoretic semantics he considers term rewriting systems without confluence restrictions as a specification language and shows that fundamental properties such as the existence of initial models or the soundness and completeness of narrowing