Open Bisimulation for the Concurrent Constraint Pi-Calculus

  • Maria Grazia Buscemi
  • Ugo Montanari
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4960)


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 à 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.


Service Level Agreement Label Transition System Process Calculus Reduction Semantic Structural Congruence 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2008

Authors and Affiliations

  • Maria Grazia Buscemi
    • 1
  • Ugo Montanari
    • 2
  1. 1.IMT Lucca Institute for Advanced StudiesItaly
  2. 2.Dipartimento di InformaticaUniversity of PisaItaly

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