Detection of Equivalent State Variables in Finite State Machine Verification

This paper proposes a new technique to detect equivalent state variables for finite state machine verification. The technique can easily be integrated with existing verification methods and significantly extends the ability of these methods to handle finite state machines (FSMs) with similar state encodings. This is of practical importance as it enlarges the class of FSMs for which verification is feasible. The proposed technique can also be used to verify combinational equivalence of FSMs with unknown correspondence between the state variables. The effectiveness of the technique is shown by experimental results on well-known benchmarks with up to 1426 state variables.