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