<?xml  version="1.0"?>
<!-- validity constraint check for Production 56(Positive Test)it is a DTD-->
<!DOCTYPE test
 [
 <!ELEMENT test ANY>
 <!ELEMENT landscape EMPTY>
 <!NOTATION gif PUBLIC "gif">
 <!ENTITY image SYSTEM "testspec/images/sunset.gif" NDATA gif>
 <!ATTLIST landscape sun ENTITY #IMPLIED>
]>
<test>
<landscape sun = "image"></landscape>
values of type ENTITY match the Name production and the ENTITY value
matches the name of an unparsed entity declared in the DTD.
</test>