static L<Pair<S>> ai_texts_xy_bothQuoted(S a, S b, S c) {
  new L<Pair<S>> l;
  for (Pair<S> p : ai_texts_dollarXY(a, b, c))
    if (isProperlyQuoted2(p.a) && isProperlyQuoted2(p.b))
      l.add(pair(unquote(p.a), unquote(p.b)));
  ret l;
}