Lazy abstractions for timed automata
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.
Cite
@article{arxiv.1301.3127,
title = {Lazy abstractions for timed automata},
author = {Frédéric Herbreteau and B. Srivathsan and Igor Walukiewicz},
journal= {arXiv preprint arXiv:1301.3127},
year = {2013}
}