SELECT DISTINCT ?uri WHERE {?uri <http://dbpedia.org/ontology/opponent> <http://dbpedia.org/resource/Ike_Clanton> . ?uri <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Person>}
Which  person has opponent Ike Clanton?
SELECT DISTINCT ?o WHERE { ?o rdf:type ontology:Person . ?o property:opponent resource:Ike_Clanton }
Wyatt Earp
The person whose opponent is Ike Clanton is [Wyatt Earp].
The man with Ike Clanton as opponent is [Wyatt Earp].
[Wyatt Earp] is the person whose opponent is him.
[Wyatt Earp] is the man he opposes.