--- a/examples/eg-24-prov-o-html-examples/rdf/create/rdf/class_Derivation.ttl	Mon May 07 09:58:04 2012 -0400
+++ b/examples/eg-24-prov-o-html-examples/rdf/create/rdf/class_Derivation.ttl	Mon May 07 10:18:49 2012 -0400
@@ -4,17 +4,39 @@
 @prefix prov: <http://www.w3.org/ns/prov#> .
 @prefix :     <http://example.com/> .
 
+:bar_chart 
+   a prov:Entity;
+   prov:wasDerivedFrom :aggregatedByRegions;  # The simplest (and least detailed) form of derivation.
+.
+
 :bar_chart
    a prov:Entity;
-   prov:wasDerivedFrom :aggregatedByRegions;
-   prov:qualifiedDerivation [
-      a prov:Derivation;
-      prov:entity :aggregatedByRegions;         
-      prov:hadGeneration :illustration;  ## More details about the activity underpinning the derivation
+   prov:wasDerivedFrom :aggregatedByRegions;  # The simple form can be accompanied by a qualified form:
+   prov:qualifiedDerivation [                  
+      a prov:Derivation;                      # An instance of Derivation provides more details
+      prov:entity      :aggregatedByRegions;  # about how :bar_chart was derived from :aggregatedRegions
+
+      :foo :bar;  # - - - - - - - - - - - - - - Arbitrary domain-specific descriptions are permitted.
+
+      # Derivations can cite the Activity involved in doing the derivation.
+      prov:hadActivity   :illustration_activity;
+
+      # They can also cite the Usage and Generation that the Activity performed to generate :bar_chart.
+      prov:hadUsage      :how_illustration_activity_used_data;
+      prov:hadGeneration :bar_chart_generation;
    ];
 .
 
-:illustration   
+:illustration_activity 
+   a prov:Activity;
+   prov:wasAttributedTo :derek;
+.
+
+:bar_chart_generation
    a prov:Generation, prov:InstantaneousEvent;
    prov:atTime "2012-04-03T00:00:01Z"^^xsd:dateTime;
 .
+
+:how_illustration_activity_used_data
+   a prov:Usage;
+.