static L<S> ai_texts(S a, S b, S c) {
  ret web_texts(ai_search_dollarX(a, b, c));
}

static L<S> ai_texts(S a, L<S> b, S c) {
  new LinkedHashSet<S> l;
  for (S _b : b)
    l.addAll(ai_texts(a, _b, c));
  ret cloneList(l);
}