for(int i=0; i<pos; i++) if (holder[i]==null) throw new Error("realbad " + i);
for(int i=pos; i<owner().elements.length; i++) {
if (holder[i]==null) holder[i] = ((Union)owner().elements[i]).epsilonForm(loc);
for(int i=0; i<pos; i++) if (holder[i]==null) throw new Error("realbad " + i);
for(int i=pos; i<owner().elements.length; i++) {
if (holder[i]==null) holder[i] = ((Union)owner().elements[i]).epsilonForm(loc);