(assert (= x4_plus 0))
(assert (= x4_minus 0))
(assert (= x2_plus 1))
(assert (= x2_minus 0))
(assert (= x1_plus 0))
(assert (= x1_minus 1))
(assert (= x0_plus 0))
(assert (= x0_minus 0))
(assert (= x3_plus 0))
(assert (= x3_minus 0))