SELECT DISTINCT ?uri WHERE { <http://dbpedia.org/resource/Jack_Ferguson> <http://dbpedia.org/ontology/child> ?x . ?x <http://dbpedia.org/property/primeminister> ?uri . }
Which child of Jack Ferguson became a Prime Minister?
SELECT DISTINCT ?b WHERE { ?u property:primeminister ?b . . resource:Jack_Ferguson property:child ?u }
Julia Gillard, Kevin Rudd
The children of Jack Ferguson became Prime Ministers are [Julia Gillard, Kevin Rudd].
Jack Ferguson's children became prime ministers [Julia Gillard, Kevin Rudd].
The kids who became prime minister  are [Julia Gillard, Kevin Rudd].
The prime minister kids are [Julia Gillard, Kevin Rudd].