--- a/model/working-copy/wd6-prov-dm-with-core.html	Mon May 21 11:21:48 2012 +0100
+++ b/model/working-copy/wd6-prov-dm-with-core.html	Mon May 21 11:56:11 2012 +0100
@@ -628,17 +628,53 @@
 <section id="section-prov-extended"> 
 <h2>PROV Extended Structures</h2>
 
-<section id="section--prov-extended-appraoch"> 
+<p>While PROV Core focuses on essential provenance structures commonly found in provenance descriptions, extended structures 
+are designed to support more advanced uses of provenance.</p>
+
+
+
+
+
+<section id="section-prov-extended-approach"> 
 <h2>Approach</h2>
 
-<p>Subtyping, expanded relations,  new relations.</p>
-
-
-<p>Agents may adopt sets of actions or steps to achieve their goals. This is captured by the notion of plan. </p>
-<p>In some  
-cases, those activities reflect the execution of a plan that was  
-designed in advance to guide the execution.  Thus,
-a plan may also be linked to an activity.  </p>
+<p>Extended structures are defined by a variety of mechanisms that we
+describe in this section: subtyping, expanded relations, optional
+identification, and new relations.</p>
+
+
+<section id="section-prov-extended-approach-subtyping"> 
+<h2>Subtyping</h2>
+
+<p>Subtyping can be applied to core types. For example, a software agent is special kind of agent, defined as follows.</p>
+
+<span class="glossary-ref" data-ref="glossary-software-agent"  data-withspan="true">
+</span>
+
+
+<p>Subtyping can also be applied to  core relations. For example, a revision is a special kind of derivation, defined as follows.</p>
+
+
+<p><span class="glossary-ref" data-ref="glossary-revision" data-withspan="true"></span></p>
+
+</section>
+
+<section id="section-prov-extended-approach-expanded-relation"> 
+<h2>Expanded Relations</h2>
+
+<p><a href="#core-structures">Section 2.1</a> shows that six concepts are mapped to binary relations in the core of PROV.  However, some advanced uses of these concepts cannot be captured by a binary relations, but require relations to be expanded to n-ary relations.</p>
+
+
+<p>To illustrate expanded relations, we consider the concept of
+association, described
+in <a href="#section-agents-attribution-association-responsibility">section
+2.1.2</a>.  Agents may adopt sets of actions or steps to achieve their
+goals in the context of an activity: this is captured by the notion of
+plan.  Hence, an activity may reflect the execution of a plan that was
+designed in advance to guide the execution.  Hence, an expanded
+association relation allows a plan a plan be linked to an
+activity. Plan and full association are defined as follows. </p>
+
 <p>
 <span class="glossary-ref" data-ref="glossary-plan"  data-withspan="true">
 </span>
@@ -650,21 +686,39 @@
 validate the execution as represented in the provenance record, to  
 manage expectation failures, or to provide explanations.</p> 
 
+<!--
 <div class="conceptexample" id="plan-example">
 <p>
 A plan can be a blog post tutorial for how to set up a web server, a list of instructions for a micro-processor execution, a cook's written recipe for a chocolate cake, or a workflow for a scientific experiment.
 </p>
 </div>
+-->
+
+<p>
+<span class="glossary-ref" data-ref="glossary-activityAssociation"  data-withspan="true"></span>
+</p>
 
 
 <div class="conceptexample" id="association-example2">
-<p>Examples of association between an activity and an agent are:
-<ul>
-<li>an XSLT transform launched by a user based on an XSL style sheet (a plan).</li>
-</ul>
+<p>An examples of association between an activity and an agent involving a plan is:
+an XSLT transform launched by a user based on an XSL style sheet (a plan).
+
 </div>
-
-
+</section>
+
+
+<section id="section-prov-extended-approach-xxx"> 
+<h2>Optional Identification</h2>
+
+
+</section>
+
+
+<section id="section-prov-extended-approach-new-relations"> 
+<h2>New Relations</h2>
+
+
+</section>