Abstract
Timed automata are among the most widely studied models for real-time systems. Silent transitions, i.e., ε-transitions, have already been proposed in the original paper on timed automata by Alur and Dill
The present paper settles this open question. Precisely, we prove that a timed automaton such that no ε-transition with nonempty reset set lies on any directed cycle can be effectively transformed into a timed automaton without ε-transitions. Interestingly, this main result holds under the assumption of non-Zenoness and it is false otherwise.
Besides, we develop a promising new technique based on a notion of precise time which allows to show that some timed languages are not recognizable by any ε-free timed automaton.
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References
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© 1997 Springer-Verlag Berlin Heidelberg
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Diekert, V., Gastin, P., Petit, A. (1997). Removing ε-transitions in timed automata. In: Reischuk, R., Morvan, M. (eds) STACS 97. STACS 1997. Lecture Notes in Computer Science, vol 1200. Springer, Berlin, Heidelberg. https://doi.org/10.1007/BFb0023491
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DOI: https://doi.org/10.1007/BFb0023491
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