--- a/model/prov-n.html	Wed Jul 04 17:37:46 2012 -0400
+++ b/model/prov-n.html	Thu Jul 05 13:12:45 2012 +0100
@@ -2495,7 +2495,21 @@
 
 <div class="anexample">
 <p>
-TODO: an example of extended syntax.</p>
+<a href="#component6">Collections</a> are sets of entities, whose membership can be expressed using the <span class="name">memberOf</span> relation.  The following example shows how one can express membership for an extension of Collections, namely sets of key-value pairs. The notation is a variation of that used for Collections membership, in which the elements of the set are pairs. The name of the relation is qualified with the extension-specific namespace <span class="name">http://example.org/dictionaries</span>.
+</p>
+<pre class="codeexample">
+  prefix dictExt &lt;http://example.org/dictionaries&gt;
+  dictExt:memberOf(mId; d, {(k1,e1), (k2,e2), (k3,e3)}, []) 
+</pre>
+
+Note that the generic <code class="content"><a class="grammarRef"
+ href="#prod-extensibilityExpression">extensibilityExpression</a></code> production  above allows for alternative notations to be used for expressing membership, if the designers of the extensions so desire. Here is an alternate syntax that is consistent with the productions:
+<pre class="codeexample">
+  prefix dictExt &lt;http://example.org/dictionaries&gt;
+  dictExt:memberOf(d, dictExt:set(dictExt:pair(k1,e1), dictExt:pair(k2,e2), dictExt:pair(k3,e3), [dictExt:uniqueKeys="true"]); mId)
+</pre>
+
+  
 </div>