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arXiv · 1301.3127

Lazy abstractions for timed automata

Frédéric Herbreteau·B. Srivathsan·Igor Walukiewicz
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Abstract

We consider the reachability problem for timed automata. A standard solution to this problem involves computing a search tree whose nodes are abstractions of zones. For efficiency reasons, they are parametrized by the maximal lower and upper bounds (LU-bounds) occurring in the guards of the automaton. We propose an algorithm that is updating LU-bounds during exploration of the search tree. In order to keep them as small as possible, the bounds are refined only when they enable a transition that is impossible in the unabstracted system. So our algorithm can be seen as a kind of lazy CEGAR algorithm for timed automata. We show that on several standard benchmarks, the algorithm is capable of keeping very small LU-bounds, and in consequence reduce the search space substantially.

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Frédéric Herbreteau, B. Srivathsan, Igor Walukiewicz. 2013-01-18. Lazy abstractions for timed automata. https://arxiv.org/abs/1301.3127

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