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