static L<AIConcept> aiConceptsPrioritized() {
  new L<AIConcept> l;
  for (S id : priorityConcepts) {
    AIConcept c = getAIConcept(id);
    if (c == null) print("Warning: Not found " + id);
    addIfNotNull(l, c);
  }
  Set<S> index = new HashSet(priorityConcepts);
  for (AIConcept c : aiConceptsByAge())
    if (!index.contains(c.globalID))
      l.add(c);
  ret l;
}