--- a/examples/eg-24-prov-o-html-examples/rdf/create/rdf/property_hadUsage.ttl	Mon Sep 10 15:21:35 2012 +0100
+++ b/examples/eg-24-prov-o-html-examples/rdf/create/rdf/property_hadUsage.ttl	Mon Sep 10 10:50:21 2012 -0400
@@ -3,7 +3,6 @@
 @prefix owl:  <http://www.w3.org/2002/07/owl#> .
 @prefix prov: <http://www.w3.org/ns/prov#> .
 @prefix :     <http://example.com/> .
-
 :digestedProteinSample1
    a prov:Entity;
    prov:wasDerivedFrom :proteinSample;
@@ -11,9 +10,10 @@
       a prov:Derivation;
       prov:hadUsage [
          a prov:Usage;
-         :treatmentEnzyme :Trypsin;
+         prov:entity :Trypsin;
+        prov:hadRole :treatmentEnzyme;
       ];
    ];
+   prov:entity :proteinSample;
 .
-
 :proteinSample a prov:Entity .