procedure Postorder (Tree : in Tree_Type) is
                  x:Integer:=1;

      begin
         if Tree /= null then
            Postorder (Tree => Tree.Left);    -- Traverse Left subtree
            Postorder (Tree => Tree.Right);   -- Traverse Right subtree
         elsif Tree = null then
            x:=0;
         end if;
         if x=0 then
            Checked_Process (Tree.Info);
            x:=1;
         end if;
      end Postorder;