static IF1<S, Double> dm_languageDetectionScorer(S lang1, S lang2) {
  LS pos = dm_examplesForLanguageFromCRUD(lang1);
  LS neg = dm_examplesForLanguageFromCRUD(lang2);
  S task = lang1 + " vs " + lang2 + " n=" + joinWithSlash(litorderedset(l(pos), l(neg)));
  ret re -> scoreRegexpIC(re, pos, neg);
}