The Research archive provides access to all Research articles published in past issues of Communications of the ACM.
We introduce bisimulation up to congruence as a technique for proving language equivalence of nondeterministic finite automata.
As the equivalence problem is essential in many applications, we need algorithms that avoid the worst-case complexity as often as possible. In "Hacking Nondeterminism with Induction and Coinduction," Filippo Bonchi and Damien…