<rdf:RDF xmlns:ex="http://www.example.org/ns#"
         xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">

  <!-- check rdf:parseType="Collection" -->

  <rdf:Description rdf:about="http://example.org/node1">
     <ex:prop1 rdf:parseType="Collection">
       <rdf:Description>
          <ex:prop2 rdf:resource="http://example.org/node2" />
       </rdf:Description>
       <rdf:Description>
          <ex:prop3 rdf:resource="http://example.org/node3" />
       </rdf:Description>
     </ex:prop1>
  </rdf:Description>
</rdf:RDF>