public Union nonTerminal(String str, PreSequence[][] s, boolean synthetic, boolean dropAll) {
Union n = str.equals(startSymbol) ? g : nt.get(str);
if (n == null) nt.put(str, n = new Union(str, synthetic));
public Union nonTerminal(String str, PreSequence[][] s, boolean synthetic, boolean dropAll) {
Union n = str.equals(startSymbol) ? g : nt.get(str);
if (n == null) nt.put(str, n = new Union(str, synthetic));