PREFIX foaf:
PREFIX vcard:
CONSTRUCT { ?x vcard:N _:v .
_:v vcard:givenName ?gname .
_:v vcard:familyName ?fname }
WHERE
{
{ ?x foaf:firstname ?gname } UNION { ?x foaf:givenname ?gname } .
{ ?x foaf:surname ?fname } UNION { ?x foaf:family_name ?fname } .
}