<?xml version='1.0'?>
<!DOCTYPE sxe SYSTEM "notfound.dtd" [
<!ENTITY % incent SYSTEM "sxe.ent">
%incent;
]>
<sxe id="elem1">
<elem1 attr1='first'>
<!-- comment -->
<elem2>
<elem3>
<elem4>
<?test processing instruction ?>
</elem4>
</elem3>
</elem2>
</elem1>
</sxe>