@prefix owl: <http://www.w3.org/2002/07/owl#>.
@prefix swrl: <http://www.w3.org/2003/11/swrl#>.
@prefix : <foo://bla/names#>.
:sue :child :barbara; :sibling :john.
:john :name "John"; :child :alice, :bob;  :sibling :sue.
:x a swrl:Variable.
:y a swrl:Variable.
:z a swrl:Variable.
 :uncleAuntRule a swrl:Imp;
   swrl:head ([ a swrl:IndividualPropertyAtom;
                 swrl:propertyPredicate :uncleAunt;
                 swrl:argument1 :y ;   swrl:argument2 :z ]);
   swrl:body ([ a swrl:IndividualPropertyAtom;
                 swrl:propertyPredicate :child;
                 swrl:argument1 :x ;   swrl:argument2 :y ]
              [ a swrl:IndividualPropertyAtom;
                 swrl:propertyPredicate :sibling;
                 swrl:argument1 :x ;   swrl:argument2 :z ]).