title: SPARQL entity lists inside select queries
body: <p>In the following DBpedia query, is there a way to consolidate the UNIONs into a single pattern?</p>
  
  <pre><code>PREFIX prop: &lt;http://resedia.org/ontology/&gt;
  PREFIX res: &lt;http://resedia.org/resource/&gt;
  SELECT DISTINCT ?language ?label 
  WHERE { 
    {res:Spain prop:language ?language} 
      UNION
    {res:France prop:language ?language}
      UNION
    {res:Italy prop:language ?language}
    ?language rdfs:label ?label .
    FILTER langMatches(lang(?label), "en") 
  }
  </code></pre>
  
  <p>The <a href="http://www.w3.org/TR/rdf-sparql-query/#collections" rel="nofollow noreferrer">SPARQL spec</a> mentions something about RDF collections but I don't really understand what it's describing. It seemed like the following syntax should work, but it didn't.</p>
  
  <pre><code>PREFIX prop: &lt;http://resedia.org/ontology/&gt;
  PREFIX res: &lt;http://resedia.org/resource/&gt;
  SELECT DISTINCT ?language ?label 
  WHERE { 
    (res:Spain res:France res:Italy) prop:language ?language
    ?language rdfs:label ?label .
    FILTER langMatches(lang(?label), "en") 
  }
  </code></pre>
  
  <p>Is there a way to define a list (or "multiset", or "bag") of URIs like this inside a SELECT query?</p>