title: Specify multiple rdf:types in a SPARQL query
body: <p>I have a SPARQL query like this</p>
  
  <pre><code>PREFIX prefix: &lt;http://example.org/ns#&gt;
  SELECT *
  WHERE 
  {
      ?x rdf:type ?type .
  }
  </code></pre>
  
  <p>Suppose now I want to specify the type of <code>?type</code> as being either <code>prefix:type1</code> or <code>prefix:type2</code>; how should this be done?</p>