In this paper, we first introduce a new lower bound technique for the state complexity of transformations of automata. Namely we suggest considering the class of full automata in lower bound analysis. Then we apply such technique to the complementation of nondeterministic ωautomata and obtain several lower bound results. Particularly, we prove anΩ((0.76n)) lower bound for Büchi complementation,...

The precise complexity of complementing Büchi automata is an intriguing and long standing problem. While optimal complementation techniques for finite automata are simple – it suffices to determinize them using a simple subset construction and to dualize the acceptance condition of the resulting automaton – Büchi complementation is more involved. Indeed, the construction of an EXPTIME complemen...

In the automata-theoretic approach to model checking we check the emptiness of the product of a system with an automaton for the complemented specification. This gives rise to two automata-theoretic problems: complementation of word automata, which is used in order to generate , and the emptiness problem, to which model checking is reduced. Both problems have numerous other applications, and ha...