+ x 0 x + 0 x x + s x s y s s + x y * x 0 0 * 0 x 0 * s x s y s + * x y + x y sum nil 0 sum cons x l + x sum l prod nil s 0 prod cons x l * x prod l + 2 0 0 s 1 * 2 sum 1 nil 0 cons 2 prod 1 FULL ./TRS/Cime/list-sum-prod.trs