Bisimulation by Unification*

  • Paolo Baldan
  • Andrea Bracciali
  • Roberto Bruni
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 2422)


We propose a methodology for the analysis of open systems based on process calculi and bisimilarity. Open systems are seen as coordinators (i.e. terms with place-holders), that evolve when suitable components (i.e. closed terms) fill in their place-holders. The distinguishing feature of our approach is the definition of a symbolic operational semantics for coordinators that exploits spatial/modal formulae as labels of transitions and avoids the universal closure of coordinators w.r.t. all components. Two kinds of bisimilarities are then defined, called strict and large, which differ in the way formulae are compared. Strict bisimilarity implies large bisimilarity which, in turn, implies the one based on universal closure. Moreover, for process calculi in suitable formats, we show how the symbolic semantics can be defined constructively, using unification. Our approach is illustrated on a toy process calculus with CCS-like communication within ambients.


Operational Semantic Proof System Algebraic Format Proof Rule Universal Closure 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    M. Abadi and M. P. Fiore. Computing symbolic models for verifying cryptographic protocols. In Proc. 14th IEEE Computer Security Foundations Workshop, pp. 160–173. IEEE, 2001.Google Scholar
  2. 2.
    R. Allen and D. Garlan. A Formal Basis for Architectural Connectors. ACM TOSEM, 6(3), pp. 213–249, 1997.CrossRefGoogle Scholar
  3. 3.
    L. F. Andrade, J. L. Fiadeiro, J. Gouveia, G. Koutsoukos and M. Wermelinger. Coordination for Orchestration. In Coordination Models and Languages, 5th Int. Conference COORDINATION. Lect. Notes in Comput. Sci. 2315 pp. 5–13. Springer 2002.Google Scholar
  4. 4.
    F. Baader and W. Snyder. Unification theory. In Handbook of Automated Reasoning. Elsevier Science, 2000.Google Scholar
  5. 5.
    M. Boreale. Symbolic trace analysis of cryptographic protocols. In Proc. ICALP’01, Lect. Notes in Comput. Sci. 2076, pp. 667–681. Springer, 2001.Google Scholar
  6. 6.
    R. Bruni, D. de Frutos-Escrig, N. Martí-Oliet, and U. Montanari. Bisimilarity congruences for open terms and term graphs via tile logic. In Proc. CONCUR 2000, Lect. Notes in Comput. Sci. 1877, pp. 259–274. Springer, 2000.Google Scholar
  7. 7.
    R. Bruni, U. Montanari, and F. Rossi. An interactive semantics of logic programming. Theory and Practice of Logic Programming, 1(6):647–690, 2001.zbMATHCrossRefMathSciNetGoogle Scholar
  8. 8.
    L. Caires. A Model for Declarative Programming and Specification with Concurrency and Mobility. PhD thesis, Departamento de Informática, Universidade Nova de Lisboa, 1999.Google Scholar
  9. 9.
    L. Caires and L. Cardelli. A spatial logic for concurrency (part I). In Proc. TACS 2001, Lect. Notes in Comput. Sci. 2215, pp. 1–37. Springer, 2001.Google Scholar
  10. 10.
    L. Caires and L. Cardelli. A spatial logic for concurrency (part II). In Proc. CONCUR 2002. Lect. Notes in Comput. Sci., Springer, 2002. To appear.Google Scholar
  11. 11.
    L. Cardelli and A. D. Gordon. Anytime, anywhere. modal logics for mobile ambients. In Proc. POPL 2000, pp. 365–377. ACM, 2000.Google Scholar
  12. 12.
    L. Cardelli and A. D. Gordon. Mobile ambients. In Proc. FoSSaCS’98, Lect. Notes in Comput. Sci. 1378, pp. 140–155. Springer, 1998.Google Scholar
  13. 13.
    E. M. Clarke, S. Jha, and W. Marrero. Using state space exploration and a natural deduction style message derivation engine to verify security protocols. In Proc. PROCOMET’98. Chapmann & Hall, 1998.Google Scholar
  14. 14.
    R. De Simone. Higher level synchronizing devices in MEIJE-SCCS. TCS, 37:245–267, 1985.zbMATHCrossRefGoogle Scholar
  15. 15.
    J. L. Fiadeiro, T. Maibaum, N. Martí-Oliet, J. Meseguer, and I. Pita. Towards a verification logic for rewriting logic. In Proc. WADT’99, LNCS 1827, pp. 438–458. Springer, 2000.Google Scholar
  16. 16.
    F. Gadducci and U. Montanari. The tile model. In Proof, Language and Interaction: Essays in Honour of Robin Milner. MIT Press, 2000.Google Scholar
  17. 17.
    M. Hennessy and H. Lin. Symbolic bisimulations. Theoret. Comp. Sci., 138:353–389, 1995.zbMATHCrossRefMathSciNetGoogle Scholar
  18. 18.
    A. Herold and J. Siekmann. Unification in abelian semi-groups. Journal of Automated Reasoning, 3(3):247–283, 1987.zbMATHCrossRefMathSciNetGoogle Scholar
  19. 19.
    K. G. Larsen and L. Xinxin. Compositionality through an operational semantics of contexts. In Proc. ICALP’90, Lect. Notes in Comput. Sci. 443, pp. 526–539. Springer, 1990.Google Scholar
  20. 20.
    J. J. Leifer and R. Milner. Deriving bisimulation congruences for reactive systems. In Proc. CONCUR 2000, Lect. Notes in Comput. Sci. 1877, pp. 243–258. Springer, 2000.Google Scholar
  21. 21.
    R. Milner. A Calculus of Communicating Systems, LNCS 92. Springer, 1980.zbMATHGoogle Scholar
  22. 22.
    U. Montanari and V. Sassone. Dynamic congruence vs. progressing bisimulation for CCS. Fundamenta Informaticae, 16:171–196, 1992.zbMATHMathSciNetGoogle Scholar
  23. 23.
    G. Plotkin. A structural approach to operational semantics. Technical Report DAIMI FN-19, Aarhus University, Computer Science Department, 1981.Google Scholar
  24. 24.
    A. Rensink. Bisimilarity of open terms. Inform. and Comput., 156(1–2):345–385, 2000.zbMATHCrossRefMathSciNetGoogle Scholar
  25. 25.
    P. Sewell. From rewrite rules to bisimulation congruences. In Proc. CONCUR’98, Lect. Notes in Comput. Sci. 1466, pp. 269–284. Springer, 1998.Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2002

Authors and Affiliations

  • Paolo Baldan
    • 1
  • Andrea Bracciali
    • 2
  • Roberto Bruni
    • 2
  1. 1.Dipartimento di InformaticaUniversitá Ca’ Foscari di VeneziaItalia
  2. 2.Dipartimento di InformaticaUniversitá di PisaItalia

Personalised recommendations