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