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Forward Analysis of Updatable Timed Automata

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Abstract

Timed automata are a widely studied model. Its decidability has been proved using the so-called region automaton construction. This construction provides a correct abstraction for the behaviours of timed automata, but it suffers from a state explosion and is thus not used in practice. Instead, algorithms based on the notion of zones are implemented using adapted data structures like DBMs. When we focus on forward analysis algorithms, the exact computation of all the successors of the initial configurations does not always terminate. Thus, some abstractions are often used to ensure termination, among which, a widening operator on zones.

In this paper, we study in detail this widening operator and the corresponding forward analysis algorithm. This algorithm is most used and implemented in tools like KRONOS and UPPAAL. One of our main results is that it is hopeless to find a forward analysis algorithm for general timed automata, that uses such a widening operator, and which is correct. This goes really against what one could think. We then study in detail this algorithm in the more general framework of updatable timed automata, a model which has been introduced as a natural syntactic extension of classical timed automata. We describe subclasses of this model for which a correct widening operator can be found.

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References

  1. R. Alur, “Timed automata,” in Proc. 11th International Conference on Computer Aided Verification (CAV'99), Vol. 1633 of Lecture Notes in Computer Science, Springer, 1999, pp. 8-22. Invited talk.

  2. R. Alur, C. Courcoubetis, D. Dill, N. Halbwachs, and H. Wong-Toi, “An implementation of three algorithms for timing verification based on automata emptiness,” in Proc. 13th IEEE Real-Time Systems Symposium (RTSS'92), IEEE Computer Society Press, 1992, pp. 157-166.

  3. R. Alur, C. Courcoubetis, and T.A. Henzinger, “The observational power of clocks,” in Proc. 5th International Conference on Concurrency Theory (CONCUR'94), Vol. 836 of Lecture Notes in Computer Science, Springer, 1994, pp. 162-177.

  4. R. Alur and D. Dill, “Automata for modeling real-time systems,” in Proc. 17th International Colloquium on Automata, Languages and Programming (ICALP'90), Vol. 443 of Lecture Notes in Computer Science, Springer, 1990, pp. 322-335.

  5. R. Alur and D. Dill, “A theory of timed automata,” Theoretical Computer Science (TCS), Vol. 126, No. 2, pp. 183-235, 1994.

    Google Scholar 

  6. R. Alur, L. Fix, and T.A. Henzinger, “A determinizable class of timed automata,” in Proc. 6th International Conference on Computer Aided Verification (CAV'94), Vol. 818 of Lecture Notes in Computer Science, Springer, 1994, pp. 1-13.

  7. G. Behrmann, A. Fehnker, T. Hune, K.G. Larsen, P. Pettersson, J. Romijn, and F. Vaandrager, “Minimum-cost reachability for priced timed automata,” in Proc. 4th InternationalWorkshop on Hybrid Systems: Computation and Control (HSCC'01), Vol. 2034 of Lecture Notes in Computer Science, Springer, 2001, pp. 147-161.

  8. G. Behrmann, K.G. Larsen, J. Pearson, C.Weise, andW. Yi, “Efficient timed reachability analysis using clock difference diagrams,” in Proc. 11th International Conference on Computer Aided Verification (CAV'99), Vol. 1633 of Lecture Notes in Computer Science, Springer, 1999, pp. 341-353.

  9. J. Bengtsson, “Clocks, DBMs ans states in timed systems,” Ph.D. thesis, Department of Information Technology, Uppsala University, Uppsala, Sweden, 2002.

    Google Scholar 

  10. J. Bengtsson and F. Larsson, “UPPAAL, a tool for automatic verification of real-time systems,” Master's thesis, Department of Computer Science, Uppsala University, Sweden, 1996.

    Google Scholar 

  11. B. Bérard, P. Bouyer, and A. Petit, “Analysing the PGM protocol with UPPAAL,” in Proc. 2nd Workshop on Real-Time Tools (RT-TOOLS'02), Proc. published as Technical Report 2002-025, Uppsala University, Sweden, 2002.

    Google Scholar 

  12. B. Bérard, V. Diekert, P. Gastin, and A. Petit, “Characterization of the expressive power of silent transitions in timed automata,” Fundamenta Informaticae, Vol. 36, Nos. 2/3, pp. 145-182, 1998.

    Google Scholar 

  13. B. Bérard and L. Fribourg, “Automated verification of a parametric real-time program: the ABR conformance protocol,” in Proc. 11th International Conference on Computer Aided Verification (CAV'99), Vol. 1633 of Lecture Notes in Computer Science, Springer, 1999, pp. 96-107.

  14. A. Bouajjani, S. Tripakis, and S. Yovine, “On-the-fly symbolic model-checking for real-time systems,” in Proc. 18th IEEE Real-Time Systems Symposium (RTSS'97), IEEE Computer Society Press, 1997, pp. 25-35.

  15. P. Bouyer, “A new algorithm to decide emptiness of updatable timed automata,” Research Report LSV-00-9, Laboratoire Spécification et Vérification, ENS de Cachan, France, 2000.

    Google Scholar 

  16. P. Bouyer, “Untameable timed automata!” in Proc. 20th Annual Symposium on Theoretical Aspects of Computer Science (STACS'03), Vol. 2607 of Lecture Notes in Computer Science, Springer, 2003, pp. 620-631.

  17. P. Bouyer, C. Dufourd, E. Fleury, and A. Petit, “Are timed automata updatable?” in Proc. 12th International Conference on Computer Aided Verification (CAV'2000), Vol. 1855 of Lecture Notes in Computer Science, Springer, 2000, pp. 464-479.

  18. P. Bouyer, C. Dufourd, E. Fleury, and A. Petit, “Expressiveness of updatable timed automata,” in Proc. 25th International Symposium on Mathematical Foundations of Computer Science (MFCS'2000), Vol. 1893 of Lecture Notes in Computer Science, Springer, 2000, pp. 232-242.

  19. C. Choffrut and M. Goldwurm, “Timed automata with periodic clock constraints,” Journal of Automata, Languages and Combinatorics (JALC), Vol. 5, No. 4, pp. 371-404, 2000.

    Google Scholar 

  20. E.M. Clarke, O. Grumberg, S. Jha, Y. Lu, and H. Veith, “Counterexample-guided abstraction refinement,” in Proc. 12th International Conference on Computer Aided Verification (CAV'2000), Vol. 1855 of Lecture Notes in Computer Science, Springer, 2000, pp. 154-169.

  21. E. Clarke, O. Grumberg, and D. Peled, “Model-Checking,” The MIT Press: Cambridge, MA, 1999.

    Google Scholar 

  22. C. Daws, “Analyse par simulation symbolique des systémes temporisés avec KRONOS,” Research report, Verimag, 1997.

  23. C. Daws, A. Olivero, S. Tripakis, and S. Yovine, “The tool KRONOS,” in Proc. Hybrid Systems III: Veri-fication and Control (1995), Vol. 1066 of Lecture Notes in Computer Science, Springer, 1996, pp. 208-219.

  24. C. Daws and S. Tripakis, “Model-checking of real-time reachability properties using abstractions,” in Proc. 4th International Conference on Tools and Algorithms for the Construction and Analysis of Systems (TACAS'98), Vol. 1384 of Lecture Notes in Computer Science, Springer, 1998, pp. 313-329.

  25. F. Demichelis and W. Zielonka, “Controlled timed automata,” in Proc. 9th International Conference on Concurrency Theory (CONCUR'98), Vol. 1466 of Lecture Notes in Computer Science, Springer, 1998, pp. 455-469. 26. D. Dill, “Timing assumptions and verification of finite-state concurrent systems,” in Proc. of the Workshop on Automatic Verification Methods for Finite State Systems, Vol. 407 of Lecture Notes in Computer Science, Springer, 1989, pp. 197-212.

  26. K. Havelund, A. Skou, K.G. Larsen, and K. Lund, “Formal modeling and analysis of an audio/video protocol: An industrial case study using UPPAAL,” in Proc. 18th IEEE Real-Time Systems Symposium (RTSS'97), IEEE Computer Society Press, 1997, pp. 2-13.

  27. T.A. Henzinger, P.-H. Ho, and H. Wong-Toi, “HYTECH: A model-checker for hybrid systems,” Journal on Software Tools for Technology Transfer (STTT), Vol. 1, Nos. 1/2, pp. 110-122, 1997.

    Google Scholar 

  28. T. A. Henzinger, P.W.Kopke, and H.Wong-Toi, “The expressive power of clocks,” in Proc. 22nd International Colloquium on Automata, Languages and Programming (ICALP'95), Vol. 944 of Lecture Notes in Computer Science Springer, 1995, pp. 417-428.

  29. T.A. Henzinger, J.-F. Raskin, and P.-Y. Schobbens, “The regular real-time languages,” in Proc. 25th International Colloquium on Automata, Languages and Programming (ICALP'98), Vol. 1443 of Lecture Notes in Computer Science, Springer, 1998, pp. 580-591.

  30. K.G. Larsen, P. Pettersson, and W. Yi, “UPPAAL in a nutshell,” Journal of Software Tools for Technology Transfer (STTT), Vol. 1, Nos. 1/2, pp. 134-152, 1997.

    Google Scholar 

  31. S. Mukhopadhyay and A. Podelski, “Beyond region graphs: Symbolic forward analysis of timed automata,” in Proc. 19th Conference on Foundations of Software Technology and Theoretical Computer Science (FST&TCS'99), Vol. 1738 of Lecture Notes in Computer Science, Springer, 1999, pp. 232-244.

  32. S. Tripakis, “L'analyse formelle des systémes temporisés en pratique,” Ph.D. thesis, Université Joseph Fourier, Grenoble, France, 1998.

    Google Scholar 

  33. S. Tripakis and S.Yovine, “Verification of the fast reservation protocol with delayed transmission using the tool KRONOS,” in Proc. 4th IEEE Real-Time Technology and Applications Symposium (RTAS'98), IEEE Computer Society Press, 1998, pp. 165-170.

  34. S. Tripakis and S. Yovine, “Analysis of timed systems using time-abstracting bisimulations,” Formal Methods in System Design, Vol. 18, No. 1, pp. 25-68, 2001.

    Google Scholar 

  35. T. Wilke, “Specifying timed state sequences in powerful decidable logics and timed automata,” in Proc. 3rd International Symposium on Formal Techniques in Real-Time and Fault-Tolerant Systems (FTRTFT'94), Vol. 863 of Lecture Notes in Computer Science, Springer, 1994, pp. 694-715.

  36. H. Wong-Toi, “Symbolic approximations for verifying real-time systems,” Ph.D. thesis, Stanford University, USA, 1994.

    Google Scholar 

  37. M. Yannakakis and D. Lee, “An efficient algorithm for minimizing real-time transition systems,” Formal Methods in System Design, Vol. 11, No. 2, pp. 113-136, 1997.

    Google Scholar 

  38. S. Yovine, “Model-checking timed automata,” in School on Embedded Systems, Vol. 1494 of Lecture Notes in Computer Science, Springer, 1998, pp. 114-152.

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Bouyer, P. Forward Analysis of Updatable Timed Automata. Formal Methods in System Design 24, 281–320 (2004). https://doi.org/10.1023/B:FORM.0000026093.21513.31

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