title: Link object to subject in RDF domain
body: <p>I have this RDF file:</p>
  
  <pre><code>&lt;rdf:RDF
      xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
      xmlns:j.0="http://relation/"
      xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"&gt; 
    &lt;rdf:Description rdf:about="soggetto"&gt;
      &lt;j.0:Nome&gt;Vercelli&lt;/j.0:Nome&gt;
      &lt;j.0:Regione&gt;Piemonte&lt;/j.0:Regione&gt;
    &lt;/rdf:Description&gt;
    &lt;rdf:Description rdf:about="Piemonte"&gt;
      &lt;rdfs:label&gt;Piemonte&lt;/rdfs:label&gt;
    &lt;/rdf:Description&gt;
    &lt;rdf:Description rdf:about="Regione"&gt;
      &lt;rdfs:label&gt;Regione&lt;/rdfs:label&gt;
      &lt;rdf:type rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Property"/&gt;
    &lt;/rdf:Description&gt;
    &lt;rdf:Description rdf:about="Vercelli"&gt;
      &lt;rdfs:label&gt;Vercelli&lt;/rdfs:label&gt;
    &lt;/rdf:Description&gt;
    &lt;rdf:Description rdf:about="Nome"&gt;
      &lt;rdfs:label&gt;Nome&lt;/rdfs:label&gt;
      &lt;rdf:type rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Property"/&gt;
    &lt;/rdf:Description&gt;
  &lt;/rdf:RDF&gt;
  </code></pre>
  
  <p>I would like to link Piemonte and Vercelli objects (in the "soggetto" subject) with Piemonte and Vercelli subjects, and I would like to link Regione and Nome predicates (in the "soggetto" subject) with Regione and Nome subjects.</p>
  
  <p>For me, Vercelli subject is equal to Vercelli object, Piemonte subject is equal to Piemonte object, Regione predicate is equal to Regione subject, and Nome predicate is equal to Nome subject.</p>
  
  <p>How I can accomplish this?
  Can I use <code>rdf:type</code> predicate to make Vercelli object equal to Vercelli subject? 
  Or does another attribute exist?</p>