text: PREFIX  dc:  <http://purl.org/dc/elements/1.1/>
  PREFIX  ns:  <http://example.org/ns#>
  SELECT  ?title ?price
  WHERE   { ?x ns:price ?price .
            FILTER (?price < "30.5"^^<http://www.w3.org/2001/XMLSchema#float>)
            ?x dc:title ?title . }
  