static void ai_spec_searchForAnswer_trace(S s) {
  Set<Traced<S>> cluster = litciset(tracedParam(s));
  cluster = ai_cluster_forward_trace(cluster, "parses to triple");
  //print("Cluster: " + cluster);
  if (empty(cluster)) ret;
  ai_expandCluster_trace(cluster);
  //print("Cluster expanded: " + cluster);
  cluster = ai_cluster_backward_trace(cluster, "answers triple");
  //print("Cluster: " + cluster);
  if (empty(cluster)) ret;
  ai_postTriple_multi(untraceAll(cluster), "answers", s);
}