YES(?,POLY)

'Pop* with parameter subtitution (timeout of 60.0 seconds)'
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Answer:           YES(?,POLY)
Input Problem:    innermost runtime-complexity with respect to
  Rules: {a(b(x)) -> b(b(a(x)))}

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