MAYBE
* Step 1: Failure MAYBE
  + Considered Problem:
      - Strict TRS:
          ack(0(),x) -> s(x)
          ack(s(x),0()) -> ack(x,s(0()))
          ack(s(x),s(y)) -> ack(x,ack(s(x),y))
          d(x) -> if(le(x,nr()),x)
          if(false(),x) -> nil()
          if(true(),x) -> cons(x,d(s(x)))
          le(0(),y) -> true()
          le(s(x),0()) -> false()
          le(s(x),s(y)) -> le(x,y)
          nr() -> ack(s(s(s(s(s(s(0())))))),0())
          numbers() -> d(0())
      - Signature:
          {ack/2,d/1,if/2,le/2,nr/0,numbers/0} / {0/0,cons/2,false/0,nil/0,s/1,true/0}
      - Obligation:
          innermost runtime complexity wrt. defined symbols {ack,d,if,le,nr,numbers} and constructors {0,cons,false
          ,nil,s,true}
  + Applied Processor:
      Ara {heuristics_ = NoHeuristics, minDegree = 1, maxDegree = 3, araTimeout = 60, araFindStrictRules = Nothing, araSmtSolver = MiniSMT}
  + Details:
      The input can not be schown compatible.
MAYBE