 the same internal structure (unlike multiple groups, where there is no guarantee whatsoever of how their contents are structured). Tools can therefore check their validity and potentially apply specialized processing or presentation to composite tokens.</li>
  <li>You can think of a composite type as something "inside" an individual token.</li>
  </ul>
  </li>
  </ul>
  </section><section id="type-checking"><div class="header-wrapper"><h3 id="x9-2-type-checking"><bdi class="secno">9.2 </bdi>Type checking</