XPath filter 2.0 schema

Just wondering if the schema is valid:
  <complexType name="XPathType" content="textOnly" ... />

Should it be:
  <complexType name="XPathType">
    <simpleContent>
      <extension base="string">
        <attribute name="Filter">
           <simpleType>
             <restriction base="NOTATION">
               <enumeration value="intersect"/>
               <enumeration value="subtract"/>
               <enumeration value="union"/>
             </restriction>
           </simpleType>
        </attribute>
      </extension>
    </simpleContent>
  </complexType>

Merlin