   <sch:pattern name="Security Classification Policy">

      <sch:p>A Para's classification value cannot be more sensitive 
             than the Document's classification value.</sch:p> 

      <sch:rule context="Para[@classification='top-secret']">

         <sch:assert test="/Document/@classification='top-secret'">
             If there is a Para labeled "top-secret" then the Document  
             must be labeled top-secret
         </sch:assert>

      </sch:rule>

      <sch:rule context="Para[@classification='secret']">

         <sch:assert test="(/Document/@classification='top-secret') or
                           (/Document/@classification='secret')">
             If there is a Para labeled "secret" then the Document  
             must be labeled either secret or top-secret
         </sch:assert>

      </sch:rule>

      <sch:rule context="Para[@classification='confidential']">

         <sch:assert test="(/Document/@classification='top-secret') or
                           (/Document/@classification='secret') or 
                           (/Document/@classification='confidential')">
             If there is a Para labeled "confidential" then the Document  
             must be labeled either confidential, secret or top-secret
         </sch:assert>

      </sch:rule>

   </sch:pattern>