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