static L<Pair<S>> ai_texts_verified_bothQuoted(S b) {
  new L<Pair<S>> l;
  for (Pair<S> p : ai_texts_verified_dollarXY("$X", b, "$Y"))
    if (isProperlyQuoted2(p.a) && isProperlyQuoted2(p.b))
      l.add(pair(unquote(p.a), unquote(p.b)));
  ret l;
}