return EPresence.UNKNOWN;
}
EPresence result = EPresence.EMPTY;
for (int index : n.getContents()) {
Node child = xg.getNode(index);
EPresence p = child.process(this);
if (result.maybeNonEmpty() && p.maybeNonEmpty())
malformed[0] = true; // many roots
result = result.concat(p);
}
open.remove(n);