--- a/ontology/components/used/prov-dm-pe1-used-e1-e2.ttl	Sun Nov 06 12:23:09 2011 -0500
+++ b/ontology/components/used/prov-dm-pe1-used-e1-e2.ttl	Sun Nov 06 12:27:01 2011 -0500
@@ -31,3 +31,5 @@
       prov:time [ a prov:Time; rdf:value 2 ]; 
    ];
 .
+:e1 a prov:Entity .
+:e2 a prov:Entity .