public Set getUnresolvedNonterminals()	{
		Set unresolved = new HashSet();
		for (int j = 0; j < size(); j++)	{
			Rule rule = getRule(j);
			for (int i = 0; i < rule.rightSize(); i++)	{
				String sym = rule.getRightSymbol(i);
				if (Token.isTerminal(sym) == false && sym.equals(Token.BUTNOT) == false && sym.equals(Token.UPTO) == false && hasRule(sym) == false)
					unresolved.add(sym);
			}
		}
		return unresolved;
	}