--- a/model/ProvenanceModel.html Thu Aug 04 18:09:32 2011 +0100
+++ b/model/ProvenanceModel.html Thu Aug 04 22:02:17 2011 +0100
@@ -162,9 +162,9 @@
</section>
<section>
-<h3>Encoding using Abstract Syntax Notation</h3>
+<h3>Encoding using the Provenance Abstract Syntax Notation</h3>
-In this section, the example is encoded according to the Provenance data model (specified in section <a href="\data-model-concepts">concepts</a>), expressed in the Abstract Syntax Notation. Details about the Abstract Syntax Notation can be found in <a href="'#ASN-convention'">appendix</a>.
+In this section, the example is encoded according to the Provenance data model (specified in section <a href="\data-model-concepts">concepts</a>), expressed in the Provenance Abstract Syntax Notation. Details about the Provenance Abstract Syntax Notation can be found in <a href="'#PASN-convention'">appendix</a>.
<p>
Entities (construct described in <a href="#concept-Entity">Section Entity</a>). The file in its various forms and its copies are modelled as entities.
<pre>
@@ -329,7 +329,7 @@
</p>
-<p>This specification defines a data model for provenance (placeholder acronym PIDM), relies on a language, the <a href="#ASN-convention">Abstract Syntax Notation</a>, to express
+<p>This specification defines a data model for provenance (placeholder acronym PIDM), relies on a language, the <a href="#PASN-convention">Provenance Abstract Syntax Notation</a>, to express
<em>instances</em> of that data model.</p>
@@ -497,7 +497,7 @@
or <b>isGeneratedBy(e,pe,r,t)</b> holds, the values of <em>some</em> of <b>e</b>'s
attributes are determined by the activity denoted by <b>pe</b> and the
entities used by <b>pe</b>.
-Only some of the attributes values may be determined since, in an open world, not all used entities may have been asserted.
+Only some (possibly none) of the attributes values may be determined since, in an open world, not all used entities may have been asserted.
</p>
<p>Given an assertion <b>isGeneratedBy(x,pe,r)</b> or <b>isGeneratedBy(x,pe,r,t)</b>, one can
@@ -521,7 +521,7 @@
<section id="concept-Use">
<h3>Use</h3>
-<div class='issue'>Various comments raised at <a href="http://www.w3.org/2011/prov/track/issues/64">ISSUE-64</a>.</div>
+<div class='pending'>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>
@@ -550,19 +550,22 @@
-<p>Given an assertion <b>uses(pe,x,r)</b> or <b>uses(pe,x,r,t)</b>,
-at least one value of <b>x</b>'s attributes is a pre-condition for the activity denoted by <b>pe</b> to terminate.</p>
+<p>
+Given a process execution <b>pe</b>, entity <b>e</b>, role <b>r</b>, and optional time <b>t</b>, if
+ assertion <b>uses(pe,e,r)</b> or <b>uses(pe,e,r,t)</b> holds,
+the existence of the value of an attribute of <b>e</b>' is a pre-condition for the activity denoted by <b>pe</b> to terminate.</p>
-<p>Given an assertion <b>uses(pe,x,r)</b> or <b>uses(pe,x,r,t)</b>, one can
-infer that the use of the thing denoted by <b>x</b> precedes the end
+<p>Given a process execution <b>pe</b>, entity <b>e</b>, role <b>r</b>, and optional time <b>t</b>, if
+ assertion <b>uses(pe,e,r)</b> or <b>uses(pe,e,r,t)</b> holds, one can
+infer that the use of the thing denoted by <b>e</b> precedes the end
of <b>pe</b> and follows the beginning of <b>pe</b>. Furthermore, we
-can infer that the generation of the thing <b>x</b> always precedes
+can infer that the generation of the thing denoted by <b>e</b> always precedes
its use. </p>
-<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='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>
</section>
@@ -772,15 +775,17 @@
<section id="concept-Time">
<h3>Time</h3>
-<p><dfn id="dfn-time">Time</dfn> is defined according to [[!ISO8601]].</p>
+<p><dfn id="dfn-time">Time instants</dfn> are defined according to xsd:dateTime [[!XMLSCHEMA-2]].</p>
+
+
<p>It is OPTIONAL to assert time in use, generation, and process execution.</p>
-<div class='issue'> Is it appropriate to refer to ISO8601. Point in Time, Interval? This is <a href="http://www.w3.org/2011/prov/track/issues/58">ISSUE-58</a>.</div>
+<div class='pending'> Is it appropriate to refer to ISO8601. Point in Time, Interval? This is <a href="http://www.w3.org/2011/prov/track/issues/58">ISSUE-58</a>.</div>
<section>
<h4>Temporal Events</h4>
-Four kinds of discrete events underpin the provenance language. They are:
+Four kinds of discrete events underpin the PIDM data model. They are:
<ol>
<li>Generation of an entity by a process execution: identifies the final instant of an entity's creation timespan, after which the characterized thing represented by an entity becomes available for use.</li>
<li>Use of an entity by a process execution: identifies the first instant of an entity's consumption timespan.</li>
@@ -826,6 +831,13 @@
<p>A <dfn id="dfn-Role">role</dfn> is a label that names the function assumed by an entity or
an agent with respect to a specific process execution.</p>
+<div class='note'>It may be useful to distinguish between a role name and a role type, similarly to
+ parameter names and parameter types in a programming language procedure.
+Currently, all the constraints and definitions pertaining to roles in the
+specification should be understood as role names.</div>
+
+
+
<p>Use, Generation, and Control assertions MUST contain a role. Roles
are mandatory since they allow for uniform data structures. To facilitate
the writing of these assertions when a role is unknown by the
@@ -839,9 +851,9 @@
where unspecified1 is an unspecified role.
</p>
-<p> The set of all Use (resp. Generation, Control) assertions that refer to a given process execution MUST contain at most one occurrence of a given role.</p>
+<p> The set of all Use (resp. Generation, Control) assertions that refer to a given process execution MUST contain at most one occurrence of a given role. The rationale for this requirement is that when provenance is used to replay execution, roles are used to determine which values must be associated with which input (resp. output, control channel) of a process execution.</p>
-<div class='issue'>Decide the level of requirements: MUST/SHOULD and justify. This is <a href="http://www.w3.org/2011/prov/track/issues/40">ISSUE-40</a> and <a href="http://www.w3.org/2011/prov/track/issues/41">ISSUE-41</a>.</div>
+<div class='pending'>Decide the level of requirements: MUST/SHOULD and justify. This is <a href="http://www.w3.org/2011/prov/track/issues/40">ISSUE-40</a> and <a href="http://www.w3.org/2011/prov/track/issues/41">ISSUE-41</a>. MUST is confirmed. </div>
<p>The interpretation of a role is specific to the process execution it relates
@@ -1032,8 +1044,8 @@
</section>
-<section id='ASN-convention'>>
- <h3>Abstract Syntax Notation Conventions</h3>
+<section id='PASN-convention'>>
+ <h3>Provenance Abstract Syntax Notation Conventions</h3>
<ul>
<li>Language constructs are represented as <b>name(arg0, arg1, ...)</b>, where the name of the construct occurs first, and is followed by its arguments.</li>
<li>For use, generation, and derivation event, the first argument is the 'effect' (i.e. most recent item) and the second argument is the 'cause' (i.e. least recent item). This order is compatible with the temporal layout of the graphical notation.