YES(?,POLY) 'Pop* with parameter subtitution (timeout of 60.0 seconds)' ----------------------------------------------------------- Answer: YES(?,POLY) Input Problem: innermost runtime-complexity with respect to Rules: { exp(x, 0()) -> s(0()) , exp(x, s(y)) -> *(x, exp(x, y)) , *(0(), y) -> 0() , *(s(x), y) -> +(y, *(x, y)) , -(0(), y) -> 0() , -(x, 0()) -> x , -(s(x), s(y)) -> -(x, y)} Proof Output: The input was oriented with the instance of POP* as induced by the precedence exp > *, - > *, exp ~ - and safe mapping safe(exp) = {}, safe(0) = {}, safe(s) = {1}, safe(*) = {2}, safe(+) = {1, 2}, safe(-) = {1} . For your convenience, here is the input in predicative notation: Rules: { exp(x, 0();) -> s(; 0()) , exp(x, s(; y);) -> *(x; exp(x, y;)) , *(0(); y) -> 0() , *(s(; x); y) -> +(; y, *(x; y)) , -(y; 0()) -> 0() , -(0(); x) -> x , -(s(; y); s(; x)) -> -(y; x)}