ON THE RATIONAL BEHAVIORS OF CONCURRENT TIMERS

In this paper, we study the concurrent behaviors of timers with arbitr ary delays. Timers are modeled as synchronized products of automata, a nd we investigate formal languages satisfying constraints on the delay s of each timer. Under very general assumptions, we prove that the con current behavior of two timers is rational. We give explicit automata to recognize these languages, which can be used as models in the speci fication and verification of timed processes.