Rule for OWL restriction

Human have all of their parents Humans.

<owl:Class rdf:ID='Human'>
   <owl:subClassOf>
      <owl:Restriction>
         <owl:onProperty     rdf:resource='#parent' />
         <owl:allValuesFrom  rdf:resource='#Human' />
      </owl:Restriction>
   </owl:subClassOf>
</owl:Class>

Corresponding RDF rule :

<cos:rule>
 <cos:if>
    ?x   rdf:type      ?class
    ?x   not::c:parent ?res
    ?res not::rdf:type c:Human
 </cos:if>
 <cos:then>
    ?x rdf:type c:Human
 </cos:then>
</cos:rule>