MAYBE
* Step 1: Failure MAYBE
  + Considered Problem:
      - Strict TRS:
          append(add(N,X),Y) -> add(N,append(X,Y))
          append(nil(),Y) -> Y
          f_1(pair(X,Z),N,M,Y) -> f_2(lt(N,M),N,M,Y,X,Z)
          f_2(false(),N,M,Y,X,Z) -> pair(add(M,X),Z)
          f_2(true(),N,M,Y,X,Z) -> pair(X,add(M,Z))
          f_3(pair(Y,Z),N,X) -> append(qsort(Y),add(X,qsort(Z)))
          lt(0(),s(X)) -> true()
          lt(s(X),0()) -> false()
          lt(s(X),s(Y)) -> lt(X,Y)
          qsort(add(N,X)) -> f_3(split(N,X),N,X)
          qsort(nil()) -> nil()
          split(N,add(M,Y)) -> f_1(split(N,Y),N,M,Y)
          split(N,nil()) -> pair(nil(),nil())
      - Signature:
          {append/2,f_1/4,f_2/6,f_3/3,lt/2,qsort/1,split/2} / {0/0,add/2,false/0,nil/0,pair/2,s/1,true/0}
      - Obligation:
          innermost runtime complexity wrt. defined symbols {append,f_1,f_2,f_3,lt,qsort,split} and constructors {0
          ,add,false,nil,pair,s,true}
  + Applied Processor:
      MI {miKind = Automaton Nothing, miDimension = 3, miUArgs = NoUArgs, miURules = NoURules, miSelector = Nothing}
  + Details:
      Incompatible
MAYBE