MAYBE
* Step 1: Failure MAYBE
  + Considered Problem:
      - Strict TRS:
          a__U11(X1,X2,X3) -> U11(X1,X2,X3)
          a__U11(tt(),M,N) -> a__U12(tt(),M,N)
          a__U12(X1,X2,X3) -> U12(X1,X2,X3)
          a__U12(tt(),M,N) -> s(a__plus(mark(N),mark(M)))
          a__U21(X1,X2,X3) -> U21(X1,X2,X3)
          a__U21(tt(),M,N) -> a__U22(tt(),M,N)
          a__U22(X1,X2,X3) -> U22(X1,X2,X3)
          a__U22(tt(),M,N) -> a__plus(a__x(mark(N),mark(M)),mark(N))
          a__plus(N,0()) -> mark(N)
          a__plus(N,s(M)) -> a__U11(tt(),M,N)
          a__plus(X1,X2) -> plus(X1,X2)
          a__x(N,0()) -> 0()
          a__x(N,s(M)) -> a__U21(tt(),M,N)
          a__x(X1,X2) -> x(X1,X2)
          mark(0()) -> 0()
          mark(U11(X1,X2,X3)) -> a__U11(mark(X1),X2,X3)
          mark(U12(X1,X2,X3)) -> a__U12(mark(X1),X2,X3)
          mark(U21(X1,X2,X3)) -> a__U21(mark(X1),X2,X3)
          mark(U22(X1,X2,X3)) -> a__U22(mark(X1),X2,X3)
          mark(plus(X1,X2)) -> a__plus(mark(X1),mark(X2))
          mark(s(X)) -> s(mark(X))
          mark(tt()) -> tt()
          mark(x(X1,X2)) -> a__x(mark(X1),mark(X2))
      - Signature:
          {a__U11/3,a__U12/3,a__U21/3,a__U22/3,a__plus/2,a__x/2,mark/1} / {0/0,U11/3,U12/3,U21/3,U22/3,plus/2,s/1,tt/0
          ,x/2}
      - Obligation:
          innermost runtime complexity wrt. defined symbols {a__U11,a__U12,a__U21,a__U22,a__plus,a__x
          ,mark} and constructors {0,U11,U12,U21,U22,plus,s,tt,x}
  + Applied Processor:
      MI {miKind = Automaton Nothing, miDimension = 3, miUArgs = NoUArgs, miURules = NoURules, miSelector = Nothing}
  + Details:
      Incompatible
MAYBE