static PairS gazelle_singleChangedWord_ifMoreThanOneWord(S inputA, S inputB, O... _) {
  O tokenizer = optPar tokenizer(_, gazelle_zip_defaultTokenizer());
  if (countTokens((LS) callF(tokenizer, inputA)) <= 1) null;
  if (countTokens((LS) callF(tokenizer, inputB)) <= 1) null;
  ret gazelle_singleChangedWord(inputA, inputB, _);
}

static PairS gazelle_singleChangedWord_ifMoreThanOneWord(PairS inputs, O... _) {
  ret gazelle_singleChangedWord_ifMoreThanOneWord(inputs.a, inputs.b, _);
}