<my:test 
  xmlns:my="http://www.w3.org/XML/2008/xsdl-exx/ns1" 
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://www.w3.org/XML/2008/xsdl-exx/ns1 sgd2.xsd"
>
 <!--* If the schema is good, all of these will be valid *-->
 <my:ea>
  <my:a>An 'ea' element contains just an 'a', or nothing.</my:a>
 </my:ea>
 <my:ea>
  <!--* An 'ea' element contains just an 'a', or nothing. *-->
 </my:ea>
 <my:e0><!--* An 'e0' element contains nothing; is it substitutable for ea? *--></my:e0>
 <my:eb>
  <my:b>An 'eb' element contains just a 'b', or nothing.</my:b>
 </my:eb>
 <my:eb>
  <!--* An 'eb' element contains just a 'b', or nothing. *-->
 </my:eb>
</my:test>