static L<PairS> ai_findProbableSingularPluralPairs(Set<S> words) {
  ret ai_findSuffixAddedElementsInSet(words, "s");
}

static L<PairS> ai_findProbableSingularPluralPairs(S s) {
  ret ai_findProbableSingularPluralPairs(ai_extractPhrases(s));
}