generic 
	type Elem is private;

package VEREM_L is	-- verem listaban tarolva
	type Verem is limited private;
	
        procedure Push ( v: in out Verem; e: Elem );
        procedure Pop ( v: in out Verem );
        function Top ( v: Verem ) return Elem;
	function isEmpty ( v: Verem ) return BOOLEAN;
private
	type Node;
	type Pointer is access Node;
	type Node is record
			data: Elem;
			next: Pointer := null;
		end record;
	type Verem is record	top:  Pointer := null;	end record;
end VEREM_L;