class WALL

create 
	make

feature 

	make (init_bottles: INTEGER) is
		require
			positive_bottles: init_bottles >= 0
		do
			bottles := init_bottles
		end;

	remove is
		require
			bottles_exist: bottles > 0
		do
			bottles := bottles - 1
		end;

	bottles: INTEGER;

	description: STRING is
		do
			if bottles = 0 then
				Result := "No"
			else
				Result := bottles.out
			end
			Result.append (" bottle")
			if bottles /= 1 then
				Result.append ("s")
			end
			Result.append (" of beer")
		end;

	empty: BOOLEAN is
		do
			Result := bottles = 0
		end;
	
end -- class WALL