Nested structures in the Compact syntax

element SONG {
  element TITLE { text },
  element COMPOSER {
    element NAME {
      element GIVEN { text },
      element FAMILY { text }
    }
  }+,
  element PRODUCER {
    element NAME {
      element GIVEN { text },
      element FAMILY { text }
    }
  }*,
  element PUBLISHER { text }?,
  element LENGTH { text }?,
  element YEAR { text }?,
  element ARTIST { text }+
}