--- a/model/ProvenanceModel.html Wed Sep 07 07:47:54 2011 +0100
+++ b/model/ProvenanceModel.html Wed Sep 07 09:08:02 2011 +0100
@@ -742,24 +742,40 @@
<section id="expression-Use">
<h3>Use</h3>
-<div class='resolved'>Various comments raised at <a href="http://www.w3.org/2011/prov/track/issues/64">ISSUE-64</a>.</div>
-
-<p><dfn id="dfn-Use">Use</dfn> represents the consumption of a characterized thing by an activity.</p>
-<p>A Use assertion, <span class="name">used(pe,e,r,t)</span>:
+<p>In PIDM, a <dfn id="dfn-Use">use expression</dfn> is a representation of a world event: the consumption of a characterized thing by an activity. The representation includes a description of the function of this thing with respect to the activity.</p>
+
+<div class='grammar'>
+<span class="nonterminal">use</span> :=
+<span class="name">used</span>
+<span class="name">(</span>
+<span class="nonterminal">identifier</span>
+<span class="name">,</span>
+<span class="nonterminal">identifier</span>
+<span class="name">,</span>
+<span class="nonterminal">role</span>
+[<span class="name">,</span>
+<span class="nonterminal">time</span>]
+<span class="name">)</span><br/>
+<br/>
+</div>
+
+
+<p>An instance of a use expression, noted <span class="name">used(pe,e,r,t)</span> in the Provenance Abstract Syntax notation:
<ul>
-<li> refers to a process execution <span class="name">pe</span>;
-<li> refers to an entity <span class="name">e</span>, representing the characterized thing that is used;
-<li> contains a <a href="#expression-Role">role</a> <span class="name">r</span>;
+<li> refers to a process execution <span class="name">pe</span>, which represents the consuming activity;
+<li> refers to an entity <span class="name">e</span>, representing the characterized thing that is consumed;
+<li> contains a <a href="#expression-Role">role</a> <span class="name">r</span>, which describes the function of this thing with respect to the activity;
<li> MAY contain a "use time" <span class="name">t</span>, the time at which the characterized thing was used.</p>
</ul>
</p>
-<p>
+<p>The following use assertion
<pre class="example">
used(pe1,e1,in,t)
</pre>
+states that the activity, represented by process execution identified by <span class="name">pe1</span> consumed a characterized thing, represented by entity identified by <span class="name">e1</span>, with role <span class="name">in</span>, at time <span class="name">t</span>.
</p>
@@ -790,6 +806,8 @@
<div class='issue'>Should we define a taxonomy of use? This is <a href="http://www.w3.org/2011/prov/track/issues/23">ISSUE-23</a>.</div>
+
+<div class='resolved'>Various comments raised at <a href="http://www.w3.org/2011/prov/track/issues/64">ISSUE-64</a>.</div>
</section>