Verification of I/O trace set inclusion for a class of non-deterministic finite state machines

The author generalizes a transformation of the composition of two relations introduced earlier and then illustrates its use by analyzing the problem of I/O trace set inclusion of two synchronous nondeterministic finite-state machines. It is shown that the expression describing the inclusion of sets of traces can be transformed into a polynomial-time algorithm verifying a simulation relation, if the larger machine is k-step observably nondeterministic, i.e., a machine in which the selection of the next state can be identified by observing distinct I/O sequences of length of up to k