@prefix owl: <http://www.w3.org/2002/07/owl#>.
@prefix :<http://example.org#>.

:livesIn a owl:FunctionalProperty; a owl:ObjectProperty.
:alice a :Person; :name "Alice"; :livesIn :athens.
:bob a :Person; :name "Bob"; :livesIn :brussels.
:athens a :City.
:brussels a :City.
[ a owl:AllDifferent; owl:members (:alice :bob :athens :brussels)].