YES(?,POLY) 'Pop* with parameter subtitution (timeout of 60.0 seconds)' ----------------------------------------------------------- Answer: YES(?,POLY) Input Problem: innermost runtime-complexity with respect to Rules: { admit(x, nil()) -> nil() , admit(x, .(u, .(v, .(w(), z)))) -> cond(=(sum(x, u, v), w()), .(u, .(v, .(w(), admit(carry(x, u, v), z))))) , cond(true(), y) -> y} Proof Output: The input was oriented with the instance of POP* as induced by the precedence admit > cond and safe mapping safe(admit) = {1}, safe(nil) = {}, safe(.) = {1, 2}, safe(w) = {}, safe(cond) = {1, 2}, safe(=) = {1, 2}, safe(sum) = {1, 2, 3}, safe(carry) = {1, 2, 3}, safe(true) = {} . For your convenience, here is the input in predicative notation: Rules: { admit(nil(); x) -> nil() , admit(.(; u, .(; v, .(; w(), z))); x) -> cond(; =(; sum(; x, u, v), w()), .(; u, .(; v, .(; w(), admit(z; carry(; x, u, v)))))) , cond(; true(), y) -> y}