MAYBE
* Step 1: Failure MAYBE
  + Considered Problem:
      - Strict TRS:
          U11(mark(X)) -> mark(U11(X))
          U11(ok(X)) -> ok(U11(X))
          U12(mark(X)) -> mark(U12(X))
          U12(ok(X)) -> ok(U12(X))
          __(X1,mark(X2)) -> mark(__(X1,X2))
          __(mark(X1),X2) -> mark(__(X1,X2))
          __(ok(X1),ok(X2)) -> ok(__(X1,X2))
          active(U11(X)) -> U11(active(X))
          active(U11(tt())) -> mark(U12(tt()))
          active(U12(X)) -> U12(active(X))
          active(U12(tt())) -> mark(tt())
          active(__(X,nil())) -> mark(X)
          active(__(X1,X2)) -> __(X1,active(X2))
          active(__(X1,X2)) -> __(active(X1),X2)
          active(__(__(X,Y),Z)) -> mark(__(X,__(Y,Z)))
          active(__(nil(),X)) -> mark(X)
          active(isNePal(X)) -> isNePal(active(X))
          active(isNePal(__(I,__(P,I)))) -> mark(U11(tt()))
          isNePal(mark(X)) -> mark(isNePal(X))
          isNePal(ok(X)) -> ok(isNePal(X))
          proper(U11(X)) -> U11(proper(X))
          proper(U12(X)) -> U12(proper(X))
          proper(__(X1,X2)) -> __(proper(X1),proper(X2))
          proper(isNePal(X)) -> isNePal(proper(X))
          proper(nil()) -> ok(nil())
          proper(tt()) -> ok(tt())
          top(mark(X)) -> top(proper(X))
          top(ok(X)) -> top(active(X))
      - Signature:
          {U11/1,U12/1,__/2,active/1,isNePal/1,proper/1,top/1} / {mark/1,nil/0,ok/1,tt/0}
      - Obligation:
          innermost runtime complexity wrt. defined symbols {U11,U12,__,active,isNePal,proper
          ,top} and constructors {mark,nil,ok,tt}
  + Applied Processor:
      Ara {heuristics_ = NoHeuristics, minDegree = 1, maxDegree = 3, araTimeout = 60, araFindStrictRules = Nothing, araSmtSolver = MiniSMT}
  + Details:
      The input can not be schown compatible.
MAYBE