app app app fold f x nil x app app app fold f x app app cons y z app app f y app app app fold f x z app app plus 0 y y app app plus app s x y app s app app plus x y app app times 0 y 0 app app times app s x y app app plus app app times x y y sum app app fold add 0 prod app app fold mul app s 0 app 2 fold 0 nil 0 cons 0 plus 0 0 0 s 0 times 0 sum 0 add 0 prod 0 mul 0 FULL ./TRS/higher-order/ToyamaRTA04/Ex5Folding.trs