static L<GazelleTree> gazelle_reasonWithPreprocessing(S input1, O... _) {
  F0<GazelleEvalContext> contextMaker = cast assertNotNull("Need contextMaker", optPar contextMaker(_));
  S userName = stringPar userName(_);
  bool debug = boolPar debug(_);
  bool debugPreprocessing = boolPar debugPreprocessing(_);
  
  Collection<GInterpretable> interpretables = gazelle_preprocess(input1, _);
  
  if (debugPreprocessing) {
    print("Got " + n_entries(interpretables) + " interpretables.");
    printIndentLines(interpretables);
  }
  
  new L<GazelleTree> l2;
  for (GInterpretable intp : interpretables)
    addAll(l2, dm_gazelle_reasonAboutChatInput_v2(userName, intp.text, paramsPlus(_, acceptablePurposes := litset(""))));
  ret l2;
}