_:vb51194652	<http://www.w3.org/ns/r2rml#predicateMap>	_:vb51194651 .
_:vb51194652	<http://www.w3.org/ns/r2rml#objectMap>	_:vb51194653 .
_:vb51194653	<http://www.w3.org/ns/r2rml#column>	"last_name" .
_:vb51194651	<http://www.w3.org/ns/r2rml#constant>	<http://xmlns.com/foaf/0.1/lastName> .