fun indsaet (AneTrae(ft,n,mt) , MOR::xs , p) = AneTrae(ft,n, indsaet(mt,xs,p))
  | indsaet (AneTrae(ft,n,mt) , FAR::xs , p) = AneTrae(indsaet(ft,xs,p),n,mt)
  | indsaet (AneTrae(ft,n,mt) , [] , p)      = AneTrae(ft,p,mt)
  | indsaet (AneLeaf , [] , p)               = AneLeaf
  | indsaet (AneLeaf , xs , p)               = AneLeaf;