Question: What is the president whose lieutenants are Winston Bryant and Joe Purcell?
SPARQL query:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX onto: <http://dbpedia.org/ontology/>
SELECT DISTINCT ?uri WHERE { ?uri onto:lieutenant <http://dbpedia.org/resource/Winston_Bryant> . ?uri onto:lieutenant <http://dbpedia.org/resource/Joe_Purcell> . ?uri rdf:type onto:President}