PREFIX foaf: <http://xmlns.com/foaf/0.1/> 
PREFIX dbo: <http://dbpedia.org/ontology/>  
PREFIX dbr: <http://dbpedia.org/resource/> 
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
SELECT DISTINCT ?name ?birth 
WHERE {
  ?person dbo:birthPlace dbr:London .
  ?person dbo:occupation dbr:Actor  .
  ?person foaf:name ?name . 
  ?person dbo:birthDate ?birth 
  FILTER (?birth > "1930-01-01"^^xsd:date) .  
  FILTER NOT EXISTS { ?person dbo:deathDate ?death. }
}
