Section: New Results

Timed Systems

The time progress assumption is at the core of the semantics of real-time formalisms. It is also the major obstacle to the development of partial-order techniques for real-time distributed systems since the events are ordered both by causality and by their occurrence in time. Anyway, extended free choice safe time Petri nets (TPNs) were already identified as a class where partial order semantics behaves well. In [37] , we show that, for this class, the time progress assumption can even be dropped (time may go back in case of concurrency), which establishes a nice relation between partial-order semantics and time progress assumption.

In coopération with Nantes and UPMC, an in-depth study of the expressiveness of time Petri nets was completed [20] . With roughly the same partners, we have extended th ITA (Interrupt Timed Automata) by parametrizing both guards and clock rates while preserving the decidability results (RP 2013, not yet in HAL).