// returns list(pair(id, rule))
static L<PairS> mL_rules_addGlobalIDsIfAuthed(S listName) {
  L<S> l = splitAtEmptyLines(mL_raw(listName));
  L<PairS> withIDs = combineWithGlobalIDs(l);
  bool change = false;
  for (PairS p : withIDs) {
    if (empty(p.a)) p.a = aGlobalID();
    change = true;
  }
  if (change && isMechAuthed()) {
    newText = joinWithEmptyLines(map(l, func(PairS p) {
      prependGlobalIDInNewLineAndIndent(p.a, p.b) }));
    editMechList("NL Logic Rules w/IDs", newText);
  }
  ret l;
}