app app map f nil nil app app map f app app cons x xs app app cons app f x app app map f xs app sum app app cons x xs app app plus x app sum xs app size app app node x xs app s app sum app app map size xs app app plus 0 x 0 app app plus app s x y app s app app plus x y app 2 map 0 nil 0 cons 0 sum 0 plus 0 size 0 node 0 s 0 0 0 FULL ./TRS/higher-order/Bird/TreeSize.trs