title: SPARQL regular expression not match
body: <p>I want to get all the movies without "The Lord of the rings" string in the title. I tried this at the <a href="http://data.linkedmdb.org/snorql" rel="nofollow noreferrer">Linked Movie Database SPARQL endpoint</a>, but it doesn't work. What is wrong?</p>
  
  
  
  <pre class="lang-none prettyprint-override"><code>PREFIX m: &lt;http://data.linkedmdb.org/resource/movie/&gt;
  SELECT DISTINCT *  WHERE {
     ?film dc:title ?titulo_pelicula.
     FILTER NOT EXISTS { 
        FILTER (regex(?titulo_pelicula, "The Lord of the Rings","i")) . 
     }
  }
  </code></pre>