Using the notion of progress measures, we discuss verification methods for proving that a program satisfies a property specified by an automaton having finite nondeterminism. Such automata can express any safety property. Previous methods, which can be derived from the method presented here, either rely on transforming the program or are not to complete. In contrast, our ND progress measures describe a homomorphism from the unaltered program to a canonical specification automaton and constitute a complete verification method. The canonical specification automaton is obtained from the classical subset construction and a new subset construction, called historization.