(aql-query
   ( select "s1" ( property any "root" subject ) )
   ( select "p1" ( property any "root" predicate ) )
   ( select "o1" ( property any "root" object ) )
   ( select "p2" ( property any "nested" predicate ) )
   ( select "o2a" ( property string "nested" object ) )
   ( select "o2b" ( property IRI "nested" object ) )

   (join left ("nested") (comp-eq (property any "root" object) (property any "nested" subject)))
)
