ibm51i01.xml

<?xml version="1.0"?>
<!DOCTYPE root SYSTEM "ibm51i01.dtd" [
  <!ELEMENT root ANY>
]>
<root>
  <a> Element type a </a>
  <b> Element type b </b>
</root>
<!--* a invalid test: tests P51 VC: Proper Group/PE Nesting *-->