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