<http://test.org> <http://www.w3.org/ns/rdfa#usesVocabulary> <http://x.com/>.
<http://test.org/alice/posts/trouble_with_bob> <http://x.com/title> "The trouble with Bob".
<http://test.org/alice/posts/jos_barbecue> <http://x.com/title> "Jo's Barbecue".