public boolean belongsInLambdaSet(String variable, Grammar grammar,
			Set lambdaSet) {
		if (isVariableWithLambdaProduction(variable, grammar))
			return true;
		GrammarChecker gc = new GrammarChecker();
		Production[] productions = GrammarChecker.getProductionsOnVariable(
				variable, grammar);
		for (int k = 0; k < productions.length; k++) {
			if (isReducableToLambdaProduction(productions[k], lambdaSet)) {
				return true;
			}
		}
		return false;
	}