Running finite_automata on and.fa . ===== and.fa ===== states : [ one_even, one_odd, two_even, two_odd, zero_even, zero_odd ] accept : [ one_even ] alphabet : [ 0, 1 ] start : zero_even tests : no [ ] yes [ 0 ] no [ 1, 0 ] yes [ 0, 1, 0, 1, 0, 1, 0, 1 ] transitions : one_even x 1 => one_odd one_even x 0 => two_even one_odd x 1 => one_even one_odd x 0 => two_odd two_even x 1 => two_odd two_even x 0 => zero_even two_odd x 1 => two_even two_odd x 0 => zero_odd zero_even x 0 => one_even zero_even x 1 => zero_odd zero_odd x 0 => one_odd zero_odd x 1 => zero_even analysis : It's a strict DFA. Running inputs and tests : '' => no (ok) '0' => yes (ok) '10' => no (ok) '01010101' => yes (ok) Passed all 4 tests. Diagram created in file 'and.png'