<?xml version="1.1"?>
<!DOCTYPE foo [
<!ELEMENT foo (bar)>
<!ATTLIST foo xmlns:a CDATA #IMPLIED>
<!ELEMENT bar EMPTY>
<!ATTLIST bar xmlns:a CDATA #IMPLIED>
]>
<!-- 1.1 style prefix unbinding -->
<foo xmlns:a="http://example.org/namespace">
 <bar xmlns:a=""/>
</foo>
