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