--- a/model/prov-constraints.html	Thu Aug 09 15:05:56 2012 +0100
+++ b/model/prov-constraints.html	Thu Aug 09 17:28:07 2012 +0100
@@ -2121,6 +2121,14 @@
 <span class="name">wasAssociatedWith(_assoc; a,ag,_pl,[])</span>.
 </p>
 </div>
+
+<div class="remark">
+  In the above inference, <span class="name">_pl</span> is an
+  existential variable, so it can be
+  merged with a constant identifier, another existential variable, or a
+  placeholder <span class="name">-</span>, as explained
+  in the definition of <a>merging</a>.
+  </div>
 <hr />
 <p id='delegation-inference_text'> Delegation relates agents where one agent acts on behalf of
 another, in the context of some activity.  The supervising agent
@@ -2144,12 +2152,13 @@
 
 
 <div class="remark">
-  Note that the two associations between the agents and the activity
+  The two associations between the agents and the activity
   may have different identifiers, different plans, and different
   attributes.  In particular, the plans of the two agents need not be
   the same, and one, both, or neither can be the placeholder <span class="name">-</span>
   indicating that there is no plan, because the existential variables
-  <span class="name">_pl1</span> and <span class="name">_pl2</span> can be replaced with constant identifiers or
+  <span class="name">_pl1</span> and <span class="name">_pl2</span>
+  can be replaced with constant identifiers, existential variables, or
   placeholders <span class="name">-</span> independently, as explained
   in the definition of <a>merging</a>.
   </div>