public int compare(Object o1, Object o2) {
		Production p1 = (Production) o1, p2 = (Production) o2;
		if (start.equals(p1.getLHS())) {
			if (p1.getLHS().equals(p2.getLHS()))
				return 0;
			else
				return -1;
		}
		if (start.equals(p2.getLHS()))
			return 1;
		return p1.getLHS().compareTo(p2.getRHS());
	}