The language defined by an F. A. (Finite Automata) is the set of input string it accepts. A string x is accepted by a FA if d (q 0 , x) Î F. So, the language accepted by M is L(M) = { x | d (q 0 , x) Î F}. DFA A1 and A2, if L(A1)=L(A2), DFA A1 is Equivalence to A2.