Theoretical Computer Science
The benefits of relaxing punctuality
Journal of the ACM (JACM)
Event-clock automata: a determinizable class of timed automata
Theoretical Computer Science
Algorithmic analysis of programs with well quasi-ordered domains
Information and Computation - Special issue: LICS 1996—Part 1
ICALP '92 Proceedings of the 19th International Colloquium on Automata, Languages and Programming
Verifying Networks of Timed Processes (Extended Abstract)
TACAS '98 Proceedings of the 4th International Conference on Tools and Algorithms for Construction and Analysis of Systems
Better is Better than Well: On Efficient Verification of Infinite-State Systems
LICS '00 Proceedings of the 15th Annual IEEE Symposium on Logic in Computer Science
On the Language Inclusion Problem for Timed Automata: Closing a Decidability Gap
LICS '04 Proceedings of the 19th Annual IEEE Symposium on Logic in Computer Science
Universality and language inclusion for open and closed timed automata
HSCC'03 Proceedings of the 6th international conference on Hybrid systems: computation and control
Decidability and complexity results for timed automata via channel machines
ICALP'05 Proceedings of the 32nd international conference on Automata, Languages and Programming
HSCC'05 Proceedings of the 8th international conference on Hybrid Systems: computation and control
Universality Analysis for One-Clock Timed Automata
Fundamenta Informaticae - Fundamentals of Software Engineering 2007: Selected Contributions
Weak Alternating Timed Automata
ICALP '09 Proceedings of the 36th Internatilonal Collogquium on Automata, Languages and Programming: Part II
Universality Analysis for One-Clock Timed Automata
Fundamenta Informaticae - Fundamentals of Software Engineering 2007: Selected Contributions
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During the last years, timed automata have become a popular model for describing the behaviour of real-time systems. In particular, there has been much research on problems such as language inclusion and universality. It is well-known that the universality problem is undecidable for the class of timed automata with two or more clocks. Recently, it was shown that the problem becomes decidable if the automata are restricted to operate on a single clock variable. However, existing algorithms use a region-based constraint system and suffer from constraint explosion even for small examples. In this paper, we present a zone-based algorithm for solving the universality problem for single-clock timed automata. We apply the theory of better quasi-orderings, a refinement of the theory of well quasi-orderings, to prove termination of the algorithm. We have implemented a prototype based on our method, and checked universality for a number of timed automata. Comparisons with a region-based prototype confirm that zones are a more succinct representation, and hence allow a much more efficient implementation of the universality algorithm.