Relating Linear and Branching Model Checking
Vardi, Moshe Y.
The difference in the complexity of branching and linear model checking has been viewed as an argument in favor of the branching paradigm. In particular, the computational advantage of CTL model checking over LTL model checking makes CTL a popular choice, leading to efficient model-checking tools for this logic. Can we use these tools in order to verify linear properties? In this paper we relate branching and linear model checking. With each LTL formula psi, we associate a CTL formula psi_A that is obtained from psi by preceding each temporal operator by the universal path quantifier A . We first describe a number of attempts to utilize the tight syntactic relation between psi and psi_A in order to use CTL model-checking tools in the process of checking the formula psi. Neither attempt, however, suggests a method that is guaranteed to perform better than usual LTL model checkers. We then claim that, in practice, LTL model checkers perform nicely on formulas with equivalences of CTL. In fact, they often proceed essentially as the ones for CTL.