static S ai_standardAnswer_dollarVars(S s) {
  for (Pair<S> p : ai_texts_xy_bothQuoted("$X", "is a standard answer to", "$Y")) {
    SS match = matchDollarVarsIC(p.b, s);
    if (match != null)
      ret formatDollarVars(p.a, match);
  }
  null;
}