MAYBE
MAYBE
TRS:
 {
  app(app(mapbt(), f), app(app(app(branch(), x), l), r)) ->
  app(
     app(app(branch(), app(f, x)), app(app(mapbt(), f), l)),
     app(app(mapbt(), f), r)
  ),
                    app(app(mapbt(), f), app(leaf(), x)) ->
  app(leaf(), app(f, x))
 }
 DUP: We consider a duplicating system.
  Trs:
   {
    app(app(mapbt(), f), app(app(app(branch(), x), l), r)) ->
    app(
       app(app(branch(), app(f, x)), app(app(mapbt(), f), l)),
       app(app(mapbt(), f), r)
    ),
                      app(app(mapbt(), f), app(leaf(), x)) ->
    app(leaf(), app(f, x))
   }
  Fail