static void nlLogic_iterate_withOnFail(NLLogicChecker_v2 c, Exp e, final NLLogicChecker_v2.Matching m, final Runnable onMatch, final VF1<Exp> onFail) {
  if (e cast And) {
    final Exp b = e.b;
    c.iterate_single(e.a, m, r {
      nlLogic_iterate_x(b, m, onMatch, onFail)
    });
    ret;
  }

  final new Flag anyResults;    
  c.iterate_single(e, m, r {
    anyResults.raise();
    callF(onMatch);
  });
  if (!anyResults.isUp())
    callF(onFail, e);
}