Project(Union(Graph(?g,
                    BGP( ?s <http://www.w3.org/2000/01/rdf-schema#subClassOf> <http://schema.org/Enumeration>)),
              Union(Graph(?g,
                          BGP( ?s <http://www.w3.org/2000/01/rdf-schema#subClassOf> ?s2 .
                               ?s2 <http://www.w3.org/2000/01/rdf-schema#subClassOf> <http://schema.org/Enumeration>)),
                    Graph(?g,
                          BGP( ?s <http://www.w3.org/2000/01/rdf-schema#subClassOf> ?s3 .
                               ?s2 <http://www.w3.org/2000/01/rdf-schema#subClassOf> <http://schema.org/Enumeration> .
                               ?s3 <http://www.w3.org/2000/01/rdf-schema#subClassOf> ?s2)))),
        {?g, ?s, ?s2, ?s3})