@prefix  :       <http://example/> .
@prefix  rdf:    <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix  foaf:   <http://xmlns.com/foaf/0.1/> .

:alice  rdf:type   foaf:Person .
:alice  foaf:name  "Alice" .
:alice  foaf:knows :bob .
:alice  :secretRelationOf :john .

:bob    rdf:type   foaf:Person .
:bob    foaf:name "Bob" .
:bob    foaf:knows :john .
:bob 	foaf:knows :bill .

:john	rdf:type	foaf:Person .
:john	foaf:name 	"John" .
:john   foaf:knows	:bill .

:bill	rdf:type foaf:Person .
:bill	foaf:name "Bill" .
:bill   foaf:knows :sarah.

:sarah	rdf:type 	foaf:Person.
:sarah	foaf:name 	"Sarah" .
:sarah	foaf:knows	:sam.

:sam	rdf:type	foaf:Person.
:sam	foaf:name	"Sam" .	