Coordination by means of Synchronous and Asynchronous Communication in Concurrent Constraint Programming

Concurrent constraint programming has been thought as providing coordination of concurrent processes on the basis of the availability and sharing of information. It classically incorporates a form of asynchronous communication via a shared store. In previous work (1,2]), we presented a new version of the ask and tell primitives which features asynchronicity and synchronicity, our approach being based on the idea of telling new information just in the case that a concurrently running process is asking for it. In this paper we focus on a semantic study of this new framework, called Sec.The authors thank K. Apt, M. Bonsangue, A. Brogi, J.W. de Bakker, F. de Boer, E. de Vinck, M. Gabbrielli, E. Horita, J. Kok, B. Le Charlier, U. Montanari, C. Palamidessi, J. Rutten, V. Saraswat, P.-Y. Schobbens, and P. Wegner for stimulating discussions on the semantics of concurrent languages.