private Production getProductionForCombination(Production production,
			String comb) {
		ProductionChecker pc = new ProductionChecker();
		String rhs = production.getRHS();
		StringBuffer buffer = new StringBuffer();
		for (int k = 0; k < rhs.length(); k++) {
			char ch = rhs.charAt(k);
			if (ProductionChecker.isTerminal(ch)
					|| isNotReplacedByLambda(ch, comb))
				buffer.append(ch);
		}
		Production p = new Production(production.getLHS(), buffer.toString());
		return p;
	}