public void addShadow(Identifier orig) {
		if (isPreserved() && !orig.isPreserved())
			orig.setPreserved();
		else if (!isPreserved() && orig.isPreserved())
			setPreserved();

		Identifier ptr = this;
		while (ptr.right != null)
			ptr = ptr.right;

		/* Check if orig is already on the ptr chain */
		Identifier check = orig;
		while (check.right != null)
			check = check.right;
		if (check == ptr)
			return;

		while (orig.left != null)
			orig = orig.left;
		ptr.right = orig;
		orig.left = ptr;
	}