<!-- -*-XML-*- -->
<book id='b1'>
  <part id='P1'>
    <chapter id='c1'>
      <section id='s1'>
        <section id='s11'/>
      </section>
      <section id='s2'/>
      <section id='s3'>
        <para id='p31'/>
      </section>
    </chapter>
    <chapter id='c2'>
      <section id='s4'/>
      <section id='s5'/>
    </chapter>
  </part>
</book>



