MAYBE
* Step 1: Failure MAYBE
  + Considered Problem:
      - Strict TRS:
          ack(0(),x) -> plus(x,s(0()))
          ack(s(x),0()) -> ack(x,s(0()))
          ack(s(x),s(y)) -> ack(x,ack(s(x),y))
          double(x) -> permute(x,x,a())
          isZero(0()) -> true()
          isZero(s(x)) -> false()
          p(0()) -> 0()
          p(s(x)) -> x
          permute(x,y,a()) -> permute(isZero(x),x,b())
          permute(y,x,c()) -> s(s(permute(x,y,a())))
          permute(false(),x,b()) -> permute(ack(x,x),p(x),c())
          permute(true(),x,b()) -> 0()
          plus(x,0()) -> x
          plus(x,s(0())) -> s(x)
          plus(x,s(s(y))) -> s(plus(s(x),y))
          plus(0(),y) -> y
          plus(s(x),y) -> plus(x,s(y))
      - Signature:
          {ack/2,double/1,isZero/1,p/1,permute/3,plus/2} / {0/0,a/0,b/0,c/0,false/0,s/1,true/0}
      - Obligation:
          innermost runtime complexity wrt. defined symbols {ack,double,isZero,p,permute,plus} and constructors {0,a,b
          ,c,false,s,true}
  + Applied Processor:
      Ara {heuristics_ = NoHeuristics, minDegree = 1, maxDegree = 3, araTimeout = 60, araFindStrictRules = Nothing, araSmtSolver = Z3}
  + Details:
      The input can not be schown compatible.
MAYBE