src/HOL/Library/Dlist.thy

   "Supremum (Set As) = fold sup As bot"
   by (simp only: Set_def Supremum_sup foldl_list_of_dlist sup.commute)
 
 end
 
-hide (open) const member fold empty insert remove map filter null member length fold
+hide_const (open) member fold empty insert remove map filter null member length fold
 
 end