--- a/model/ProvenanceModel.html Wed Sep 07 12:44:39 2011 +0100
+++ b/model/ProvenanceModel.html Wed Sep 07 13:12:21 2011 +0100
@@ -787,7 +787,7 @@
<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>.
+states that the activity, represented by the 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>
@@ -905,7 +905,7 @@
</pre>
</p>
state the existence of process-linked derivations;
-the first expresses that the activity represented by process execution <span class="name">pe4</span>, by
+the first expresses that the activity represented by the process execution <span class="name">pe4</span>, by
using the thing represented by <span class="name">e3</span> with role <span class="name">in</span> derived the
thing represented by entity <span class="name">e5</span> and generated it with
role <span class="name">attachment</span>. The second is similar for <span class="name">e3</span> and <span class="name">e2</span>, but it leaves the process execution and associated roles implicit.
@@ -1094,27 +1094,53 @@
-<p>An <dfn id="dfn-Agent">agent</dfn> represents a characterized thing capable of
+<p>An <dfn id="dfn-Agent">agent expression</dfn> is a representation a characterized thing capable of
activity.</p>
-<p> An agent construct, <span class="name">agent(e)</span>:
-<ul>
-<li> refers to an entity <span class="name">e</span>
-</ul>
+<p>In the Provenance Abstract Syntax Notation, an agent expression's text matches the <span class="nonterminal">agent</span> production of the grammar defined in this specification document.
+</p>
+
+
+<div class='grammar'>
+<span class="nonterminal">agent</span> :=
+<span class="name">agent</span>
+<span class="name">(</span>
+<span class="nonterminal">identifier</span>
+<span class="name">)</span>
+</div>
+
+
+
+<p> An agent expression, written <span class="name">agent(e)</span> in the Provenance Abstract Syntax Notation:
+ refers to an entity denoted by identifier <span class="name">e</span> and representing the entity capable of activity.
</p>
<p>A characterized thing can be asserted to be an agent or can be inferred to be
an agent by involvement in a process execution. </p>
-<p>
-<pre class="example">
-entity(alice, [Employee="1234"]) and agent(alice)
-entity(david) and wasControlledBy(pe,david)
+<p>
+With the following assertions,
+
+<pre class="example">
+entity(e1, [employee: "1234", name: "Alice"]) and agent(e1)
+
+entity(e2) and wasControlledBy(pe,e2)
</pre>
+entity denoted by <span class="name">e1</span> is asserted to be an agent, and this assertion holds irrespective of process executions it may be involved in, whereas entity denoted by <span class="name">e2</span> can be inferred to be an agent, as per the following inference.
</p>
+<div class='constraint' id='control-agent'>
+<span class='conditional'>If</span>
+ <span class="name">entity(e,av)</span>
+and
+<span class="name">wasControlledBy(pe,e)</span> hold for some identifiers
+<span class="name">pe</span>, <span class="name">e</span>, and attribute-values <span class="name">av</span>, then
+ <span class="name">agent(e)</span> also holds.
+</div>
+
+
</section>
@@ -1123,20 +1149,37 @@
<section id="expression-Control">
<h3>Control</h3>
-<p> <dfn id="dfn-Control">Control</dfn> represents the involvement of an agent or an entity in a process execution; a role qualifies this involvement.</p>
+<p> A <dfn id="dfn-Control">control expression</dfn> is a representation of the involvement of characterized thing (represented as an agent or an entity) in an activity, which is represented by a process execution; a role qualifies this involvement.</p>
-<p>A Control assertion, noted <span class="name">wasControlledBy(pe,ag,r)</span>:
+<p>In the Provenance Abstract Syntax Notation, a control expression's text matches the <span class="nonterminal">control</span> production of the grammar defined in this specification document.
+</p>
+
+
+<div class='grammar'>
+<span class="nonterminal">control</span> :=
+<span class="name">wasControlledBy</span>
+<span class="name">(</span>
+<span class="nonterminal">identifier</span>,
+<span class="nonterminal">identifier</span>,
+<span class="nonterminal">role</span>
+<span class="name">)</span>
+</div>
+
+
+<p>An instance of a control expression, noted <span class="name">wasControlledBy(pe,ag,r)</span> in the Provenance Abstract Syntax Notation :
<ul>
-<li> refers to a process execution <span class="name">pe</span>;
-<li> refers to an agent or an entity <span class="name">ag</span>;
-<li> contains a role <span class="name">r</span>.
+<li> contains an identifier <span class="name">pe</span> denoting a process execution, representing the controlled activity;
+<li> refers to an agent or an entity <span class="name">ag</span>, representing the controlling characterized thing;
+<li> contains a role <span class="name">r</span>, qualifying the involvement of the thing in the activity.
</ul>
</p>
<p>
+The following control assertion
<pre class="example">
-wasControlledBy(pe3,david,"author")
+wasControlledBy(pe3,a4,author)
</pre>
+states that the activity, represented by the process execution denoted by <span class="name">pe3</span> saw the involvement of a characterized thing, represented by entity denoted by <span class="name">a4</span> in the capacity of author.
</p>
</section>