Comparative metric semantics for concurrent Prolog

AbstractThis paper shows the equivalence of two semantics for a version of Concurrent Prolog with non-flat guards: an operational semantics based on a transition system and a denotational semantics which is a metric semantics (the domains are metric spaces). We do this in the following manner. First a uniform language L is considered, that is a language where the atomic actions have arbitrary interpretations. For this language we define an operational and a denotational semantics, and we prove that the denotational semantics is correct with respect to the operational semantics. This result relies on Banach's fixed point theorem. Techniques stemming from imperative languages are used. Then we show how to translate a Concurrent Prolog program to a program in L by selecting certain basic sets for L and then instantiating the interpretation function for the atomic actions. In this way we induce the two semantics for Concurrent Prolog and the equivalence between the two semantics

Four domains for concurrency

AbstractWe give four domains for concurrency in a uniform way by means of domain equations. The domains are intended for modelling the four possible combinations of linear time versus branching time, and of interleaving versus noninterleaving concurrency. We use the linear time, noninterleaved domain to give operational and denotational semantics for a simple concurrent language with recursion, and prove that O = D

Four domains for concurrency

AbstractWe give four domains for concurrency in a uniform way by means of domain equations. The domains are intended for modelling the four possible combinations of linear time versus branching time, and of interleaving versus noninterleaving concurrency. We use the linear time, noninterleaved domain to give operational and denotational semantics for a simple concurrent language with recursion, and prove that O = D