[Love2D] Class Inheritence Error?

main.lua

---------------------------------------------------------------
-- Amethyst
-- Created: 2012/06/05 10:02 PM
-- Version: 0.0.1
-- Website: http://www.place.com/
-- License: :) License
---------------------------------------------------------------
require("libs/32log")
require("util/types")

RESOURCES = {
	Fonts = {},
}

Fonts = RESOURCES.Fonts
local Vector1 = Vec2:new(1,2);
local Vector2 = Vec2:new(2,1);

function love.load()
	RESOURCES.Fonts["Normal"] = love.graphics.newFont(
		"resource/fonts/OpenSans-Regular.ttf", 
		16
	)
	love.graphics.setFont(Fonts.Normal)
end

function love.draw()
	love.graphics.setBackgroundColor(100,149,237)
	love.graphics.print( (Vector1:x() == Vector2:x()) and "Yes" or "No", 320, 240)
end

types.lua

------------------------------
-- Object
------------------------------
class "Object" {
	_id = 0;
	_type = "Object";
}
function Object:__init()
	self._id = math.random(0,65535);
	self._type = "Object";
end

------------------------------
-- Vector 2
------------------------------
class "Vec2" : extends("Object") {
	_id = 64;
	_type = "Vec2";
	_x = 0;
	_y = 0;
}
function Vec2:__init(x, y)
	self._x = x or 0
	self._y = y or 0
end
function Vec2:x()
	return self._x;
end
function Vec2:y()
	return self._y;
end

------------------------------
-- Vector 3
------------------------------
class "Vec3" {
	x = 0;
	y = 0;
	z = 0;
}
function Vec3:__init(x, y, z)
	self.x = x
	self.y = y
	self.z = z
end
function Vec3:x()
	return self.x
end
function Vec3:y()
	return self.y
end
function Vec3:z()
	return self.z
end