</chapter>
<part>
<title>First part</title>
+<partintro>
<para>Part intro. </para>
+</partintro>
<chapter>
<title>First chapter of first part</title>
<para>Paragraph. </para>
</part>
<part>
<title>Second part</title>
+<partintro>
<para>Part 2 intro. </para>
+</partintro>
<chapter>
<title>First chapter of second part</title>
<para>Paragraph. </para>