@prefix rs:      <http://www.w3.org/2001/sw/DataAccess/tests/result-set#> .

[]  <http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
                rs:ResultSet ;
    rs:resultVariable
                "x" ;
    rs:solution [ rs:binding  [ rs:value    "_:a" ;
                                rs:variable "x"
                              ]
                ] ;
    rs:solution [ rs:binding  [ rs:value    "_:b" ;
                                rs:variable "x"
                              ]
                ] .