YES(?,POLY)

'Pop* (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))
     , double(x) -> plus(x, x)}

Proof Output:    
  The input was oriented with the instance of POP* as induced by the precedence
  
   double > plus
  
  and safe mapping
  
   safe(plus) = {}, safe(0) = {}, safe(s) = {1}, safe(double) = {} .
  
  For your convenience, here is the input in predicative notation:
  
   Rules:
    {  plus(x, 0();) -> x
     , plus(x, s(; y);) -> s(; plus(x, y;))
     , double(x;) -> plus(x, x;)}