static L<GazelleTree> dm_gazelle_reasonAboutChatInput_v2(S userName, S content, O... _) {

  // GATHER PARAMETERS & CONTEXT

  bool debug = boolPar debug(_);

  bool debugRules = boolPar debugRules(_) || debug;

  LS preContext = cast optPar preContext(_);

  GazelleEvalContext ctx = cast optPar ctx(_);

  F0<GazelleEvalContext> contextMaker = cast optPar contextMaker(_);

  if (debugRules) print("Have ctx: " + (ctx != null) + ", contextMaker: " + (contextMaker != null));

  if (ctx == null && contextMaker != null) {

    ctx = contextMaker!;

    if (debugRules) print("Called contextMaker, got " + nRules(ctx.engine.rules));

  }

  if (ctx == null) ctx = dm_gazelle_stdEvalContext(dm_gazelle_allRulesWithComment(optPar requiredComment(_, "discord")));

  Set<S> acceptablePurposes = cast optPar acceptablePurposes(_);

  if (debug)

    print(" == PROCESSING INPUT: " + content);

  // PREPARE RULES

  // Need input as first condition

  gazelle_dropRulesNotOnInput(ctx);

  if (acceptablePurposes != null) {

    if (debugRules) {

      print("Purposes: " + acceptablePurposes);

      print("Have purposes: " + collectUnique purpose(ctx.engine.rules));

    }

    int nBefore = l(ctx.engine.rules);

    ctx.engine.dropRulesWhere(r -> !acceptablePurposes.contains(unnull(r.purpose)));

    if (debugRules) print("Retaining " + n2(ctx.engine.rules, "rule") + " of " + nBefore);

  }

  if (debugRules) print("Have rules: " + collect globalID(ctx.engine.rules));

  gazelle_addHelpers(ctx, _);

  // MAKE PARAMETERS

  O[] params = paramsPlus(paramsMinus(_, 'ctx),

    firstConditionOnly := true,

    dialogHistory := preContext);

  // TREE1 (just input)

  GazelleTree tree1 = cast optPar tree(_);

  if (tree1 == null) tree1 = GazelleTree(ctx, content);

  L<GazelleTree> l = gazelle_getChildren_withContinuations(tree1, params);

  // TREE2 (user says: ...)

  if (nempty(userName) && !boolPar skipUserName(_)) {

    GazelleTree tree2 = new(ctx, optCurly(userName) + " says: " + content);

    if (debug) print("Tree2: " + tree2);

    l.addAll(gazelle_getChildren_withContinuations(tree2, paramsPlus(_, tree2 := true)));

  }

  // TREE3 (user with id x says: ...)

  Long userID = cast optPar userID(_);

  if (userID != null && userID != 0 && !boolPar skipUserID(_)) {

    GazelleTree tree3 = new(ctx, "user with id " + userID + " says: " + content);

    l.addAll(gazelle_getChildren_withContinuations(tree3, paramsPlus(_, tree3 := true));

  }

  // DROP BAD ENTRIES, SORT

  if (boolPar skipBad(_, true)) l = [GazelleTree t : l | neq(t.prediction, 'bad)];

  gazelle_sortChildren(l);

  // MATCH ADDITIONAL CONDITIONS

  SS inputMap = gazelle_inputMapFromLineAndHistory(content, 

    listPlus(preContext, content));

  if (debug) print("reasonAbout inputMap=" + sfu(asTreeMap(inputMap)));

  for (GazelleTree t : l) {

    if (t.mr == null) continue;

    int iCond;

    do {

      iCond = t.mr.iCond;

      dm_gazelle_matchStep_statement(t,

        passParams(_, 'debug, 'dm_gazelle_matchStatementsDebug));

      dm_gazelle_matchStep_additionalInput(t, inputMap, _);

      dm_gazelle_matchStep_condition(t, _);

    } while (t.mr.iCond > iCond);

  }

  for (GazelleTree t : l) t.flush();

  // DROP UNSATISFIED ENTRIES

  int n = l(l);

  l = gazelle_dropUnsatisfiedEntries(l);

  if (debug) print("Filtered out " + (n-l(l)) + " unsatisfied entries (keeping " + l(l) + ")");

  // DROP DEFAULTS

  if (!boolPar keepDefaults(_))

    gazelle_dropMatchedDefaultRules(l, _);

  ret l;

}