Searching for just a few words should be enough to get started. If you need to make more complex queries, use the tips below to guide you.
Issue title: Fundamentals of Software Engineering 2007: Selected Contributions
Article type: Research Article
Authors: Abdulla, Parosh Aziz | Deneux, Johann | Ouaknine, Joël | Quaas, Karin | Worrell, James
Affiliations: Uppsala University, Uppsala, Sweden. [email protected]; [email protected] | Oxford University, Wellington Square Oxford, United Kingdom. [email protected] | Leipzig University, Leipzig, Germany. [email protected] | Oxford University, Wellington Square Oxford, United Kingdom. [email protected]
Note: [] Address for correspondence: Uppsala University, Dag Hammarskjölds v. 10 B 75105 Uppsala, Sweden
Abstract: This paper is concerned with the universality problem for timed automata: given a timed automaton A, does A accept all timed words? Alur and Dill have shown that the universality problem is undecidable if A has two clocks, but they left open the status of the problem when A has a single clock. In this paper we close this gap for timed automata over infinite words by showing that the one-clock universality problem is undecidable. For timed automata over finite words we show that the one-clock universality problem is decidable with non-primitive recursive complexity. This reveals a surprising divergence between the theory of timed automata over finite words and over infinite words. We also show that if ε-transitions or non-singular postconditions are allowed, then the one-clock universality problem is undecidable over both finite and infinite words. Furthermore, 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 tool based on our method, and checked universality for a number of timed automata. Comparisons with a region-based prototype tool confirm that zones are a more succinct representation, and hence allow a much more efficient implementation of the universality algorithm.
Journal: Fundamenta Informaticae, vol. 89, no. 4, pp. 419-450, 2008
IOS Press, Inc.
6751 Tepper Drive
Clifton, VA 20124
USA
Tel: +1 703 830 6300
Fax: +1 703 830 2300
[email protected]
For editorial issues, like the status of your submitted paper or proposals, write to [email protected]
IOS Press
Nieuwe Hemweg 6B
1013 BG Amsterdam
The Netherlands
Tel: +31 20 688 3355
Fax: +31 20 687 0091
[email protected]
For editorial issues, permissions, book requests, submissions and proceedings, contact the Amsterdam office [email protected]
Inspirees International (China Office)
Ciyunsi Beili 207(CapitaLand), Bld 1, 7-901
100025, Beijing
China
Free service line: 400 661 8717
Fax: +86 10 8446 7947
[email protected]
For editorial issues, like the status of your submitted paper or proposals, write to [email protected]
如果您在出版方面需要帮助或有任何建, 件至: [email protected]