subject object
http://www.openlinksw.com/virtrdf-data-formats#default-iid 
1
http://www.openlinksw.com/virtrdf-data-formats#default 
1
http://www.openlinksw.com/virtrdf-data-formats#sinv-iid 
1
http://www.openlinksw.com/virtrdf-data-formats#sinv 
1