-<!DOCTYPE a SYSTEM "a.dtd" >
-<a id="3">
- <c/>
- <b>
- <c/>
- <d/>
- <c/>
+<?xml version="1.0"?>
+<a><b>
+ <c><d/><e/><f/></c>
+ <g><h/><i/><j/></g>
+ <k><l/><m/><n/></k>
</b>
- <b/>
- <a/>
+ <o>
+ <p><q/><r/><s/></p>
+ <t><u/><v/><w/></t>
+ <x><y/><z/><aa/></x>
+ </o>
</a>
+