@prefix owl: <http://www.w3.org/2002/07/owl#>.
@prefix : <foo:bla#>.
:Person owl:hasKey (:givenName :familyName).
 _:b1 a :Person; :givenName "John"; :familyName "Doe";  :age 35 .
 _:b2 a :Person; :givenName "John"; :familyName "Doe";  :address "Main Street 1" .
 _:b3 a :Person; :givenName "Mary"; :familyName "Doe";  :age 32; :address "Main Street 1" .
 _:b4 a :Person; :givenName "Donald"; :familyName "Trump";  :age 70; :address "White House" .
#:age a owl:FunctionalProperty.