1  <a>
 2          <xi:include href="b.xml" xmlns:xi="http://www.w3.org/2001/XInclude">
 3                  <xi:fallback>There is no b.xml ... </xi:fallback>
 4          </xi:include>
 5          <xi:include href="c.xml" xmlns:xi="http://www.w3.org/2001/XInclude">
 6                  <xi:fallback>There is no c.xml ... </xi:fallback>
 7          </xi:include>
 8   
 9  </a>
10