<?xml  version="1.0"?>
<!-- validity constraint check for Production 56(negative Test)-->
<!DOCTYPE tokenizer
 [
 <!ELEMENT tokenizer ANY>
 <!ATTLIST tokenizer UniqueName ID #REQUIRED>
 ]>
<tokenizer UniqueName = "@c999">
This is a negative test for validity constraints
the value of the attribute with a type ID does not match the Name production
</tokenizer>