@prefix rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix :        <http://example/> .

:a rdf:type :Set .
:a :member 1 .
:a :member 2 .
:a :member 3 .

:b rdf:type :Set .
:b :member 1 .
:b :member 9 .

:c rdf:type :Set .
:c :member 1 .
:c :member 2 . 

:d rdf:type :Set .
:d :member 1 .
:d :member 9 .

:e rdf:type :Set .
:e :member 1 .
:e :member 2 . 

:empty rdf:type :Set .