Model-checking for real-time systems specified in Lotos

  • N. Rico
  • G. v. Bochmann
  • O. Cherkaoui
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 663)


This paper aims at describing and analyzing concurrent systems whose behavior is dependent on explicit time delays. The formal description technique Lotos [Loto 89] is extended with time intervals in the following way: actions in Lotos must occur at a time t within a given interval [t min ,t max ] relative to the previous action executed by the process. The syntax and semantics of Time Interval Lotos is given. The model is defined as a labelled transition systems with clocks associated with states and timing conditions associated with transitions. The labelled transition system derived corresponds to a timed graph model [Alur 90]. The logic TCTL (Computation Tree Logic with time) which allows quantitative operators in the formulas can be used to specify assertions. Model-checking is used to determine the truth of a TCTL-formula with respect to a labelled transition system derived from the Time Interval Lotos specification. We illustrate the approach by a simple example. We also present an alternative approach for verifying timing properties. A labelled transition system with time intervals is derived. This graph does not represent the precise evolution of the system in time. Each transition is labelled with an action and a time interval showing the range of possible time occurrences for the action.


Temporal Logic Label Transition System Computation Tree Logic Model Check Algorithm Algebraic Specification 
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.


  1. [Alur 90]
    Alur, R., Courcoubetis, C. and Dill, D., ”Model-checking for real-time systems”, Proc. of 5th IEEE Symp. on Logic in Computer Science, June 90.Google Scholar
  2. [Aspv 79]
    Aspvall, B and Shiloach, ”A polynomial time algorithm for solving systems of inequalities with two variables per inequality”, in Proc. 20th Annu. Symp. Foundations of Computer Sciences, Oct. 1979, pp.205–217.Google Scholar
  3. [Berg 84]
    Bergstra, J.A. and Klop, J.W., ”Process Algebra for Synchronous Communication”, Information and Control, 60 (1–3), 1984.Google Scholar
  4. [Bert 91]
    Berthomieu, B. and Diaz, M., ”Modeling and Verification of Time Dependent Systems Using Time Petri Nets”, IEEE Trans. on SE, 17, 3, March 1991, pp. 259–273.Google Scholar
  5. [Bolo 87]
    Bolognesi, T. and Brinskma, E., ”Introduction to the ISO specification language LOTOS”, Computer Networks and ISDN Systems, 14, 1, 1987.Google Scholar
  6. [Bolo 90a]
    Bolognesi, T., Lucidi, F. and Trigila, S., ”From Timed Petri Nets to Timed LOTOS”, Proceedings of 10th IFIP WG6.1 PSTV, June 1990.Google Scholar
  7. [Bolo 90b]
    Bolognesi, T. and Lucidi F., ”LOTOS-like process algebras with urgent or timed interactions”, FORTE 90, 1990.Google Scholar
  8. [Budk 87]
    Budkowski, S. and Dembinski, P., ”An introduction to Estelle: a specification language for distributed systems”, Computer Networks and ISDN Systems, 14, 1, 1987, pp.3–23.Google Scholar
  9. [Clar 83]
    Clarke, E., Emerson, E. and Sistla, A., ”Automatic verification of finite-state concurrent systems using temporal logic specifications: A practical approach”, in Proc. 10th ACM Symp. on Principles of Programming Languages, pp.117–126, 1983.Google Scholar
  10. [Ehri 85]
    Ehrig, H. and Mahr, B., ”Fundamentals of Algebraic Specification 1”, Springer Verlag, 1985.Google Scholar
  11. [Emer89]
    Emerson, E.A., Mok, A.K., Sistla, A.P. and Srinivasan, J., ”Quantitative temporal reasoning”, in Proceedings of workshop on Automatic Verif. Methods for Finite State Systems, June 1989.Google Scholar
  12. [Hans 91]
    Hansson, H., ”Time and Probability in Formal Design of Distributed Systems”, Ph.D. Thesis, Uppsala University, September 1991.Google Scholar
  13. [Hoar 85]
    Hoare, C., ”Communicating sequential processes”, Prentice Hall, 1985.Google Scholar
  14. [Hub 90]
    van Hulzen, W., Tilanus, P., Zuidweg, H., ”LOTOS extended with clocks”, Proceedings of FORTE'89, Noth-Holland 1990.Google Scholar
  15. [Lewi 90]
    Lewis, H.R., ”A logic of concrete time intervals”, 5th IEEE Symnposium on Logic in Computer Science, June 1990.Google Scholar
  16. [Loto 89]
    ISO/TC97/SC21, ”LOTOS: A Formal Description Technique based on the temporal ordering of observational behavior”, Tech. Report IS8807, 1989.Google Scholar
  17. [Merl 76]
    Merlin, P. and Farber, D., ”Recoverability of communication protocols-Implication of a theoretical study”, IEEE Trans. on Comm.,24,6, Sept.1976.Google Scholar
  18. [Miln 80]
    Milner, R., ”A Calculus of Communicating Systems”, LNCS 92, Springer Verlag, 1980, 171p.Google Scholar
  19. [Nico 91]
    Nicollin, X. and Sifakis, J., ”An overview and synthesis on timed process algebras”, CAV'91, Aalborg, Denmark, July 1991.Google Scholar
  20. [Quem 89]
    Quemada, J., Azcorra, A. and Frutos, D., ”A Timed Calculus for LOTOS”, Proceedings of FORTE'89, Vancouver, June 1989.Google Scholar
  21. [Rico 91]
    Rico, N., and Bochmann, G.v., ”Performance description and analysis for distributed systems using a variant of Lotos”, Proceedings 11th PSTV,1991.Google Scholar
  22. [Rico 92]
    Rico, N., and Bochmann, G.v., ”Time Interval Lotos”, Technical Report, University of Montreal, 1992.Google Scholar
  23. [SDL 87]
    CCITT SG XI, Recommendation Z.100 (1987).Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1993

Authors and Affiliations

  • N. Rico
    • 1
  • G. v. Bochmann
    • 1
  • O. Cherkaoui
    • 2
  1. 1.Département d'informatique et de recherche opérationnelleUniversité de MontréalCanada
  2. 2.Département d'informatique et de mathématiquesUniversité du Québec à MontréalCanada

Personalised recommendations