[xsl] XPath which tests that an element does not have mixed content?

Hi Folks,

Would you please recommend an XPath expression which ensures that the content 
of <author> is optional whitespace, <Person>, optional whitespace, and nothing 
else:

    <author>
        <Person>
            <name>Simon L. Peyton Jones</name>
        </Person>
    </author>

The result of the XPath expression is true if the content is as desired and 
false otherwise. The XPath should return true for the above example and false 
for the below example: 

    <author>
       The person is:
        <Person>
            <name>Simon L. Peyton Jones</name>
        </Person>
    </author>


/Roger

--~------------------------------------------------------------------
XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list
To unsubscribe, go to: http://lists.mulberrytech.com/xsl-list/
or e-mail: <mailto:xsl-list-unsubscribe(_at_)lists(_dot_)mulberrytech(_dot_)com>
--~--