.  There must be
            zero or one of these elements in a composite component VDL
            file.  If a <code>&lt;cc:interface&gt;</code> element
            does appear, there must be an accompanying
            <code>&lt;cc:implementation&gt;</code> element in the
            same VDL file.  </p>

           <p><b>Nesting of composite components</b></p>

           <p>The implementation must support nesting of composite
           components.  Specifically, it must be possible for the
           <