Question: Which incumbent of Al Gore presidential campaign wass also the president of Mike McCurry ?
SPARQL:
 SELECT DISTINCT ?uri WHERE { <http://dbpedia.org/resource/Mike_McCurry_(press_secretary)> <http://dbpedia.org/ontology/president> ?uri. <http://dbpedia.org/resource/Al_Gore_presidential_campaign,_2000> <http://dbpedia.org/ontology/incumbent> ?uri}