Project(BGP( ?subject <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://xmlns.com/foaf/0.1/Person> .
             ?subject <http://xmlns.com/foaf/0.1/name> ?name .
             ?subject <http://xmlns.com/foaf/0.1/mbox> ?mbox),
        {?subject, ?name, ?mbox})