Question: Give me all female German chancellors!
SPARQL query:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX yago: <http://dbpedia.org/class/yago/>
PREFIX prop: <http://dbpedia.org/property/>
SELECT ?uri ?string
WHERE 
{
	?uri rdf:type yago:FemaleHeadsOfGovernment.
        ?uri prop:office ?office .
        FILTER regex(?office, 'Chancellor of Germany').        
        OPTIONAL {?uri rdfs:label ?string . FILTER (lang(?string) = 'en') }
}