static int nlLogic_failureLevel_calc(ExecutedRule r) {
  if (!(r.rule instanceof FailedRule)) ret 0;
  FailedRule fr = cast r.rule;
  Exp e = fr.rule.in, lookingFor = fr.remainingCondition;
  int n = l(nlLogic_unrollAnd(e))-l(nlLogic_unrollAnd(lookingFor))+1; // TODO
  ret n <= 0 ? -1 : n;
}