svoid nlLogic_battleItOut(L<RuleWithParams> battleSpace, LS facts) {
  new Matches mm;
  new MultiMap<S> trumps;
  
  // get conflict clusters
  new Clusters<S> conflictClusters;
  new Set<S> _ruleIDs;
  for (RuleWithParams r : battleSpace) {
    addIfNotNull(_ruleIDs, r.rule.globalID);
    for (S option : unnull(r.rule.options))
      if (match_vbar("conflicts with *|trumps *", option, mm)) {
        S r1 = r.rule.globalID, r2 = mm.unq(0);
        treeSetClusters_add(conflictClusters, r1, r2);
        if (match("trumps *", option))
          trumps.put(r1, r2);
      }
  }
      
  for (S s : facts) {
    bool trump = match("rule * trumps rule *", s, mm);
    if (trump || match("rule * conflicts with rule *", s, mm)) {
      S r1 = mm.unq(0), r2 = mm.unq(1);
      if (_ruleIDs.contains(r1) && _ruleIDs.contains(r2)) {
        treeSetClusters_add(conflictClusters, r1, r2);
        if (trump)
          trumps.put(r1, r2);
      }
    }
  }
        
  if (nempty(conflictClusters))
    print("Have conflict clusters: " + sfu(conflictClusters));

  // Detect winners
  final new HashSet<S> toRemove;
  for (Collection<S> ruleIDs : uniquifyList_identity(values(conflictClusters))) {
    ruleIDs = new LinkedHashSet(ruleIDs);
    for (S id : cloneList(ruleIDs)) {
      LS losers = trumps.get(id);
      removeAll(ruleIDs, losers);
      toRemove.addAll(losers);
    }
    S winner = random(ruleIDs);
    L<S> removing = listWithout(ruleIDs, winner);
    print("Winner: " + winner + ", removing: " + removing);
    toRemove.addAll(removing);
  }
  
  // Remove losers
  if (nempty(toRemove)) {
    for (ListIterator<RuleWithParams> i = listIterator(battleSpace); i.hasNext(); )
      if (toRemove.contains(i.next().rule.globalID))
        i.remove();
    print("Rules narrowed down to: " + collect(collect(battleSpace, 'rule), 'globalID));
  }
}