Parametrized Evaluation of Temporal Logic Formulae

As soon as a program is described by a finite automata, one can efficiently verify temporal formulae of various languages (e.g. LTL, CTL,...). However this method requires to fix the different parameters of the program such as the number of processes or resources. Thus this verification is only partial. In this paper we present an algorithm valid for parametrized programs. Such programs are described by two synchronized automata where the first one represents the behaviour of a finite but unknown number of processes and the second one represents the control of these processes. Many distributed algorithms can be described by this way. Our algorithm is divided into two stages. At first it tries to build a parametrized graph independent of the number of processes. Then if the first step is successful, it can evaluate any formula of CTL by adequate algorithms.