// modifies & denaturalizes the tokens (breaks connection with full text)
static L<TokenAndRange> ai_addDollarSignToCertainTokens_withRanges(L<TokenAndRange> tokens, final Set<S> set) {
  for (TokenAndRange t : tokens)
    if (contains(set, t.token))
        t.token = "$" + t.token;
  ret tokens;
}