svoid gazelle_splitMultiRule(S ruleID) {
  PairS p = dm_textAndCommentForRule(ruleID);
  if (p == null) ret;
  
  LPair<S> lines = ai_findDoubleArrowRulesAsPairs(p.a);
  Set<S> textsNeeded = asSet(mapPairsToList gazelle_constructRuleText(lines));
  S extractedComment = "extracted from multi-rule " + ruleID;
  S deployedPrefix = "deployed as rule ";
  LS coreComments = withoutLine(tlft(t.b), "multi-rule");
  
  L<T3S> rules = dm_gazelle_allRulesWithComment(extractedComment);
  LS allComments = withoutStartingWithIC(tlft(p.b), deployedPrefix);
  S commentsForDeployed = lines_rtrim(listPlus(coreComments, extractedComment));
  new LS deployed;
  for (T3S t : rules)
    if (!textsNeeded.remove(t.a))
      gazelle_deleteRule(t.c);
    else {
      gazelle_setRuleComment(t.c, commentsForDeployed);
      deployed.add(t.c);
    }
  for (S text : textsNeeded)
    deployed.add(dm_gazelle_addRuleWithComment(text, commentsForDeployed).a);
  for (S deployedID : deployed)
    allComments.add(deployedPrefix + deployedID);
  gazelle_setRuleComment(ruleID, allComments);
}