(assert (= x0 -3))
(assert (= x1 -2))
(assert (= x2 -1))
(assert (= x3 -1))
(assert (= x4 -1))
(assert (= x5 2))
(assert (= x6 -1))
(assert (= x7 -2))
(assert (= x8 -1))
(assert (= x9 0))