language SentenceOnly 1 Sentence
  cons category Sentence Sentences
  cons extension Reader "doc.reader/sentence-v1" "reader/v1"
  cons reader sentence call "doc.reader/sentence-v1"
  cons mode Sentences cons take SentenceLiteral sentence nil
  cons leaf SentenceLiteral Sentence SentenceLiteral none
    cons style self "content" nil
  nil