Question: Who were fighting the war where the QF Hotchkiss was used?
SPARQL:
SELECT DISTINCT COUNT(?uri) WHERE { <http://dbpedia.org/resource/QF_6-pounder_Hotchkiss> <http://dbpedia.org/ontology/usedInWar> ?x . ?x <http://dbpedia.org/ontology/territory> ?uri  . ?x <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/MilitaryConflict>}