+ x 0 x + 0 x x + s x s y s s + x y + + x y z + x + y z * x 0 0 * 0 x 0 * s x s y s + * x y + x y * * x y z * x * y z app nil l l app cons x l1 l2 cons x app l1 l2 sum nil 0 sum cons x l + x sum l sum app l1 l2 + sum l1 sum l2 prod nil s 0 prod cons x l * x prod l prod app l1 l2 * prod l1 prod l2 + 2 0 0 s 1 * 2 app 2 nil 0 cons 2 sum 1 prod 1 FULL ./TRS/Cime/list-sum-prod-assoc-append.trs