MAYBE
MAYBE
TRS:
 {
  app(app(append(), app(app(append(), l1), l2)), l3) ->
  app(app(append(), l1), app(app(append(), l2), l3)),
       app(app(append(), app(app(cons(), h), t)), l) ->
  app(app(cons(), h), app(app(append(), t), l)),
                        app(app(append(), nil()), l) -> l,
      app(app(map(), f), app(app(append(), l1), l2)) ->
  app(app(append(), app(app(map(), f), l1)), app(app(map(), f), l2)),
          app(app(map(), f), app(app(cons(), h), t)) ->
  app(app(cons(), app(f, h)), app(app(map(), f), t)),
                           app(app(map(), f), nil()) -> nil()
 }
 DUP: We consider a duplicating system.
  Trs:
   {
    app(app(append(), app(app(append(), l1), l2)), l3) ->
    app(app(append(), l1), app(app(append(), l2), l3)),
         app(app(append(), app(app(cons(), h), t)), l) ->
    app(app(cons(), h), app(app(append(), t), l)),
                          app(app(append(), nil()), l) -> l,
        app(app(map(), f), app(app(append(), l1), l2)) ->
    app(app(append(), app(app(map(), f), l1)), app(app(map(), f), l2)),
            app(app(map(), f), app(app(cons(), h), t)) ->
    app(app(cons(), app(f, h)), app(app(map(), f), t)),
                             app(app(map(), f), nil()) -> nil()
   }
  Fail