Christel Baier , Nathalie Bertrand , Patricia Bouyer and Thomas Brihaye When are Timed Automata Determinizable ? Research Report LSV - 09 - 08 14 April 2009

In this paper, we propose an abstract procedure which, given a timed automaton, produces a language-equivalent deterministic infinite timed tree. We prove that under a certain boundedness condition, the infinite timed tree can be reduced into a classical deterministic timed automaton. The boundedness condition is satisfied by several subclasses of timed automata, some of them were known to be determinizable (eventclock timed automata, automata with integer resets), but some others were not. We prove for instance that strongly non-Zeno timed automata can be determinized. As a corollary of those constructions, we get for those classes the decidability of the universality and of the inclusion problems, and compute their complexities (the inclusion problem is for instance EXPSPACE-complete for strongly non-Zeno timed automata).