private void addToAllFollowSets(List nonterms, List symbols)	{
		for (int i = 0; i < nonterms.size(); i++)	{
			String nt = (String) nonterms.get(i);

			for (int j = 0; j < symbols.size(); j++)	{
				String s = (String) symbols.get(j);

				if (Nullable.isNull(s) == false)	// do not add empty word
					put(nt, s);
			}
		}
	}