What is the {mansion} for {owned by} of {William IV of the United Kingdom}
Which mansion is owned by the UK's William IV?
Which is the mansion that is owned by William IV of the United Kingdom?
SELECT DISTINCT ?z WHERE { ?z property:owned_by resource:William_IV . ?z rdf:type ontology:mansion }
select distinct ?subj where { ?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?subj . ?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P127> . ?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q130822> . ?subj <http://www.wikidata.org/entity/P31> <http://wikidata.dbpedia.org/resource/Q1802963> } 
 select distinct ?sbj where { ?sbj wdt:P127 wd:Q130822 . ?sbj wdt:P31 wd:Q1802963 } 
Clarence House