\r
# todo:\r
(* assert_unseparable (problem_of (Some"`y y") ["x (_. y y)"] []);; *)\r
+\r
+\r
+$! new failing problem\r
+# it is backtracking, but it shouldn't\r
+D (a b)\r
+C ((((((((a (v (y. y))) (v c)) ((x ((a (v (y. y))) (v c))) y)) (((a (v (y. y))) (((v c) ((((z z) b) (c. a)) (w (c. (v c))))) (w. (v. (z. (v (y. y))))))) (((v (x. (v c))) (v (x. (v c)))) (((((z z) b) (c. a)) (z z)) (b c))))) (a. ((((z z) b)(c. a)) (z z)))) (y. (z z))) (((a (v (y. y))) w) (z. x))) (w. (z. (v (y. y)))))\r
+C ((((((((z z) b) (c. a)) (z z)) ((v (y. y)) a)) (v (y. y))) ((((a (v (y. y))) (v c)) (z z)) ((a (v (y. y))) (((v c) ((((z z) b) (c. a)) (w (c. (v c))))) (w. (v. (z. (v (y. y))))))))) (z. ((v (y. y)) a)))\r
+C (((((((a (v (y. y))) w) (a b)) ((b (x. (b. a))) (b. (v. ((((z z) b) (c. a)) (z z)))))) (a. (z. (b. w)))) (x. (((w v) ((z z) (a (v (y. y))))) ((a (v (y. y))) (v c))))) (((z z) (a (v (y. y)))) (b. a)))\r
+C (((((((z z) b) (c. a)) (z z)) (b c)) (b. a)) (((v (x. (v c))) (((v (x. (v c))) ((z z) b)) (a. (w. (v. (z. (v (y. y)))))))) ((x ((a (v (y. y))) (v c))) (b. (c. y)))))\r
+C (((((((z z) b) (c. a)) (z z)) (b c)) (b. a)) (y. (x. z)))\r
+N ((((((((a (v (y. y))) w) (a b)) ((b (x. (b. a))) (b. (v. ((((z z) b) (c. a)) (z z)))))) (a. (z. (b. w)))) (x. (((w v)((z z) (a (v (y. y))))) ((a (v (y. y))) (v c))))) (((z z) (a (v (y. y)))) (b. a))) (w. ((((w v) ((z z) (a (v (y. y)))))((a (v (y. y))) (v c))) (((((v c) ((((z z) b) (c. a)) (w (c. (v c))))) (w. (v. (z. (v (y. y)))))) ((z z) a)) (y. ((v c)((((z z) b) (c. a)) (w (c. (v c)))))))))) Z\r
+N (((((((a (v (y. y))) (v c)) ((x ((a (v (y. y))) (v c))) y)) (((a (v (y. y))) (((v c) ((((z z) b) (c. a)) (w (c. (v c))))) (w. (v. (z. (v (y. y))))))) (((v (x. (v c))) (v (x. (v c)))) (((((z z) b) (c. a)) (z z)) (b c))))) (a. ((((z z) b) (c. a)) (z z)))) (y. (z z))) (((a (v (y. y))) w) (z. x))) Z\r
+N (((((((z z) b) (c. a)) (z z)) ((v (y. y)) a)) (v (y. y))) ((((a (v (y. y))) (v c)) (z z)) ((a (v (y. y))) (((v c) ((((z z) b) (c. a)) (w (c. (v c))))) (w. (v. (z. (v (y. y))))))))) Z\r
+N (((((((z z) b) (c. a)) (z z)) (b c)) (b. a)) (y. (x ((z z) a)))) Z\r
+N (((((((z z) b) (c. a)) (z z)) (b c)) (x. (((z z) b) (c. a)))) (((v c) ((((z z) b) (c. a)) (w (c. (v c))))) (w. (v. (z. (v (y. y))))))) Z\r