Question: Name the president served by a lieutenant who succeeded Bob C Riley.
SPARQL query:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX prop: <http://dbpedia.org/property/>
PREFIX onto: <http://dbpedia.org/ontology/>
SELECT DISTINCT ?uri WHERE { ?x prop:predecessor <http://dbpedia.org/resource/Bob_C._Riley> . ?uri onto:lieutenant ?x  . ?uri rdf:type onto:President}