PPaste!

  def sentenceAnagrams(sentence: Sentence): List[Sentence] = {

    def aux(occurrences: Occurrences): List[Sentence] = {
      val possibleWords = (combinations(occurrences) flatMap (dictionaryByOccurrences get)).flatten
//      val possibleWords = (occurrences flatMap (dictionaryByOccurrences get)).flatten
      Nil :: (for {
        word <- possibleWords
        rest <- aux(subtract(occurrences, wordOccurrences(word)))
      } yield word :: rest)
    }
    val occurrences = sentenceOccurrences(sentence)
    aux(occurrences)
  }