static L<WebNode> ai_index_search_dollarX(S a, S b, S c) {
  S query = isDollarVar(a) ? c : a;
  // OLD
  // ret webs_search_dollarX(webFromTriples(a, b, c), indexedWebs(query));
  // NEW
  ret webs_tripleSearch_dollarX(a, b, c, indexedWebs(query));
}