Semantics and Expressive Power of a Timed Concurrent Constraint Language

We consider a timed extension of concurrent constraint programming, called tccp. For this language we define a denotational model which is fully abstract wrt the standard notion of observables (input-output pairs). We also define a fully abstract semantics for a sublanguage of tccp, called ccpx, which essentially is standard concurrent constraint programming (ccp), provided that we interpret the parallel operator in terms of “maximal parallelism” rather than of interleaving. Finally we compare the expressive power of these languages. We show that tccp is strictly more expressive than ccpx which, in its turn, is strictly more expressive than ccp. © Springer-Verlag Berlin Heidelberg 1997.