Lazy Automata Techniques for WS1S

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My contributions

1. While I was not the author of the main idea, I helped shaped the final decision procedure and came up with several significant optimisations of the process.
2. I was the main developer of the decision procedure; I implemented numbers optimisations of the process (both minor and major).
3. I run the experiments and interpreted the results.

Abstract

We present a new decision procedure for the logic WS1S. It originates from the classical approach, which first builds an automaton accepting all models of a formula and then tests whether its language is empty. The main novelty is to test the emptiness on the fly, while constructing the automaton, and prune the constructed state space from parts irrelevant for the test. The pruning is done by a~generalization of two techniques used in antichain-based language inclusion and universality checking of finite automata: subsumption and early termination. The~richer structure of the WS1S decision problem allows us, however, to elaborate on these techniques in novel ways. Our experiments show that the proposed approach can indeed significantly outperform the classical decision procedure (implemented in the \mona~tool) as well as its recently proposed alternative based on using nondeterministic automata.

Cite us

FIEDOR Tomáš, HOLÍK Lukáš, JANKŮ Petr, LENGÁL Ondřej and VOJNAR Tomáš. Lazy Automata Techniques for WS1S. In: Proceedings of TACAS’17. Lecture Notes in Computer Science, vol. 10205. Heidelberg: Springer Verlag, 2017, pp. 407-425. ISBN 978-3-662-54576-8. ISSN 0302-9743.