@incollection{eprints120,
          author = {Maria Grazia Buscemi and Ugo Montanari},
            note = {The final publication is available at www.springerlink.com.},
       publisher = {Springer},
       booktitle = {Proceedings of the 17th European Symposium on Programming (ESOP?08)},
          editor = {Sophia Drossopoulou},
           pages = {254--268},
          volume = {4960},
            year = {2008},
          series = {Lecture Notes in Computer Science},
           title = {Open Bisimulation for the Concurrent Constraint Pi-Calculus},
             url = {http://eprints.imtlucca.it/120/},
        abstract = {The concurrent constraint pi-calculus (cc-pi-calculus) has been introduced as a model for concluding Service Level Agreements. The cc-pi calculus combines the synchronous communication paradigm of process calculi with the constraint handling mechanism of concurrent constraint programming. While in the original presentation of the calculus a reduction semantics has been proposed, in this work we investigate the abstract semantics of cc-pi processes. First, we define a labelled transition system of the calculus and a notion of open bisimilarity {\`a} la pi-calculus that is proved to be a congruence. Next, we give a symbolic characterisation of bisimulation and we prove that the two semantics coincide. Essentially, two processes are open bisimilar if they have the same stores of constraints - this can be statically checked - and if their moves can be mutually simulated. A key idea of the symbolic transition system is to have ?contextual? labels, i.e. labels specifying that a process can evolve only in presence of certain constraints. Finally, we show that the polyadic Explicit Fusions calculus introduced by Gardner and Wischik can be translated into monadic cc-pi and that such a transition preserves open bisimilarity. The mapping exploits fusions and tuple unifications as constraints. }
}