package body Stack is

   procedure Clear (Stack : in out Stack_Type) is
   begin
      Stack.Top := 0;
   end Clear;

   ----------------------------------------------------------------------------
   function isEmpty (Stack : in Stack_Type) return Boolean is
   
	  temp: Boolean := false;
	  begin
    --  return Stack.Top = 0;
	if Stack.top = 0 then
	  temp := true;
	end if;
   return temp;
   end isEmpty;

   ----------------------------------------------------------------------------
   function isFull (Stack : in Stack_Type) return Boolean is
   begin
      return Stack.Top = Stack.Max_Size;
   end isFull;

   ----------------------------------------------------------------------------
   procedure Push (Stack       : in out Stack_Type;
                   New_Element : in     Element_Type) is
   begin
      if not isFull (Stack) then
         Stack.Top := Stack.Top + 1;
         Stack.Elements (Stack.Top) := New_Element;
      else
         raise OVERFLOW;
      end if;
   end Push;

   ----------------------------------------------------------------------------
   procedure Pop (Stack          : in out Stack_Type;
                  Popped_Element :    out Element_Type) is
   begin
      if not isEmpty (Stack) then
         Popped_Element := Stack.Elements (Stack.Top);
         Stack.Top := Stack.Top - 1;
      else
         raise UNDERFLOW;
      end if;
   end Pop;
end Stack;