MAYBE
* Step 1: Failure MAYBE
  + Considered Problem:
      - Strict TRS:
          U11(tt(),M,N) -> U12(tt(),activate(M),activate(N))
          U12(tt(),M,N) -> s(plus(activate(N),activate(M)))
          U21(tt(),M,N) -> U22(tt(),activate(M),activate(N))
          U22(tt(),M,N) -> plus(x(activate(N),activate(M)),activate(N))
          activate(X) -> X
          plus(N,0()) -> N
          plus(N,s(M)) -> U11(tt(),M,N)
          x(N,0()) -> 0()
          x(N,s(M)) -> U21(tt(),M,N)
      - Signature:
          {U11/3,U12/3,U21/3,U22/3,activate/1,plus/2,x/2} / {0/0,s/1,tt/0}
      - Obligation:
          innermost runtime complexity wrt. defined symbols {U11,U12,U21,U22,activate,plus,x} and constructors {0,s
          ,tt}
  + Applied Processor:
      Ara {heuristics_ = NoHeuristics, minDegree = 1, maxDegree = 3, araTimeout = 60, araFindStrictRules = Nothing, araSmtSolver = Z3}
  + Details:
      The input can not be schown compatible.
MAYBE