<?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> 