Machine Equivalence
? Let qa and qb be two states of machines Ma and Mb respectively. States qa and qb are said to be equivalent iff, starting with qa and qb, for any sequence of input symbols applied to the two machines, the output sequences are identical. If qa and i are not identical, they are said to be distinguishable.
? Let Ma and Mb be two sequential machines. Ma and Mb are said to be eqivalent iff for every state of Ma there exists at least one equivalent state in Mb, and vice versa. Similarly, if Ma and Mb are not equivalent we say they are distinguishable.
? Two states qa and qb are equivalent if:
(1) qa and qb produce the same output values (for Mealy machines, they must produce the same outputs for all legal input conditions).
(2) For each input combination, qa and qb must have the same next state, or equivalent next states.