Simulation Subsumption in Ramsey-Based Büchi Automata Universality and Inclusion Testing.

There are two main classes of methods for checking universality and language inclusion of Büchi-automata: Rank-based methods and Ramsey-based methods While rank-based methods have a better worst-case complexity, Ramsey-based methods have been shown to be quite competitive in practice [10,9] It was shown in [10] (for universality checking) that a simple subsumption technique, which avoids exploration of certain cases, greatly improves the performance of the Ramsey-based method Here, we present a much more general subsumption technique for the Ramsey-based method, which is based on using simulation preorder on the states of the Büchi-automata This technique applies to both universality and inclusion checking, yielding a substantial performance gain over the previous simple subsumption approach of [10].