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Abstract. Timed automata have an infinite semantics. For verification purposes, one usually uses zone based abstractions w.r.t. the maximal constants to which clocks of the timed automaton are compared. We show that by distinguishing maximal lower and upper bounds, significantly coarser abstractions can be obtained. We show soundness and completeness of the new abstractions w.r.t. reachability. We demonstrate how information about lower and upper bounds can be used to optimise the algorithm for bringing a difference bound matrix into normal form.Finally, we experimentally demonstrate that the new techniques dramatically increases the scalability of the real-time model checker Uppaal.

Abstract. We present Beem -BEnchmarks for Explicit Model checkers. This benchmark set includes more than 50 parametrized models (300 concrete instances) together with their correctness properties (both safety and liveness). The benchmark set is accompanied by an comprehensive web portal, which provides detailed information about all models. The web portal also includes information about state spaces and facilities for selection of models for experiments. The address of the web portal is http://anna.fi.muni.cz/models.

No abstract

Abstract. Timed automata have an infinite semantics. For verification purposes, one usually uses zone based abstractions w.r.t. the maximal constants to which clocks of the timed automaton are compared. We show that by distinguishing maximal lower and upper bounds, significantly coarser abstractions can be obtained. We show soundness and completeness of the new abstractions w.r.t. reachability. We demonstrate how information about lower and upper bounds can be used to optimise the algorithm for bringing a difference bound matrix into normal form.Finally, we experimentally demonstrate that the new techniques dramatically increases the scalability of the real-time model checker Uppaal.