Are Timed Automata Updatable ?

Patricia Bouyer (1) , Catherine Dufourd (2) , Emmanuel Fleury (3) , Antoine Petit (1)

1 LSV - Laboratoire Spécification et Vérification [Cachan]
2 EDF - EDF
3 LaBRI - Laboratoire Bordelais de Recherche en Informatique

In classical timed automata, as dened by Alur and Dill [AD90,AD94] and since widely studied, the only operation allowed to modify the clocks is the reset operation. For instance, a clock can neither be set to a non-null constant value, nor be set to the value of another clock nor, in a non-deterministic way, to some value lower or higher than a given constant. In this paper we study in details such updates. We characterize in a thin way the frontier between decidability and undecidability. Our main contributions are the following:- We exhibit many classes of updates for which emptiness is undecidable. These classes depend on the clock constraints that are used diagonal-free or not whereas it is well known that these two kinds of constraints are equivalent for classical timed automata.- We propose a generalization of the region automaton proposed by Alur and Dill, allowing to handle larger classes of updates. The complexity of the decision procedure remains Pspace-complete.

Domaines: Autre [cs.OH]

Patricia Bouyer, Catherine Dufourd, Emmanuel Fleury, Antoine Petit. Are Timed Automata Updatable ?. 12th International Conference on Computer Aided Verification (CAV'2000), 2000, Chicago, United States. pp.464-479, ⟨10.1007/10722167_35⟩. ⟨hal-00350488⟩