<doc>
<!-- A comment -->
 <a xmlns:omegahat="http://www.omegahat.org" 
    xmlns:r="http://www.r-project.org">
  <b>
  <c>
    <b/>
  </c>
  </b>
  <b omegahat:status="foo">
   <r:d>
    <a status="xyz"/>
    <a/>
    <a status="1"/>
   </r:d>
  </b>
 </a>
</doc>