svoid gazelle_dropMatchedDefaultRules(L<GazelleTree> l, O... _) {
  L<GazelleTree> l2 = filter(l, t -> !eqic(t.lineType, "temporary fact"));
  
  new Set<S> trumpedRules;
  for (GazelleTree t : l2)
    addAll(trumpedRules, matchAll_first("trumps rule *", t.ruleComments()));
    
  L<GazelleTree> trumped = [GazelleTree t : l2 |
       contains(t.ruleComments(), "default")
    || trumpedRules.contains(t.ruleID())];

  if (nempty(trumped) && l(trumped) < l(l2)) {
    if (boolPar debug(_) || boolPar debugDefaults(_)) {
      print("Removing default/trumped rules:");
      printIndentLines(trumped);
      print("Because there are also:");
      printIndentLines(listMinusSet(l2, trumped));
    }
    l.removeAll(trumped);
  }
}