--- a/model/working-copy/prov-dm-constraints.html Tue Feb 14 10:10:08 2012 +0000
+++ b/model/working-copy/prov-dm-constraints.html Tue Feb 14 10:32:40 2012 +0000
@@ -669,7 +669,7 @@
<h2>PROV-DM Definitional Constraints and Inferences</h2>
-<p>In this section, we revisit terms and relations of PROV-DM, and examine </p>
+<p>In this section, we revisit elements and relations of PROV-DM, and examine and examine the constraints associated with their definitions. </p>
@@ -677,9 +677,6 @@
<section id="record-element">
<h3>Element</h3>
-<p>This section describes all the PROV-DM records referred to as element records. (In PROV-ASN, such records are conformant to the <span class='nonterminal'>elementRecord</span> production
-of the grammar.)</p>
-
<div class="issue">
There is still some confusion about what the identifiers really denote. For instance, are they entity identifiers or entity record identifiers. This is <a
href="http://www.w3.org/2011/prov/track/issues/183">ISSUE-183</a>.
@@ -693,43 +690,25 @@
<p>
-The assertion of an entity record states, from a given asserter's viewpoint, the existence of an entity, whose situation in the world is represented by the attribute-value pairs, which
-remain unchanged during a characterization interval, i.e. a continuous interval between two <a title="event">instantaneous events</a> in the world.
-</p>
+An <dfn>entity</dfn> is a thing in the world one wants to provide provenance for and whose situation in the world is represented by some attribute-value pairs; an entity's attribute-value pairs remain unchanged during an entity's characterization interval,
+ i.e. a continuous interval between two <a title="event">instantaneous events</a> in the world, namely its <a title="entity generation event">generation event</a> and its <a title="entity destruction event">destruction event</a>.</p>
Further considerations:
<ul>
-<li>
-The entity identifier <span class="name">id</span> contained in an entity record is expected to be unique among all the identifiers contained in the current account's records.
-This constraint is elaborated upon in <a href="#identifiable-record-in-account">identifiable-record-in-account</a>. It means that the current account does not contain any other record for
-this identifier. Effectively, <span class="name">id</span> acts as a <em>local</em> identifier for this record. In this specification, whenever we write "an entity record identified by ...
-", this identification is to be understood in the context of the account that defines it. </li>
-<li>If an asserter wishes to characterize an entity with the same attribute-value pairs over several intervals, then they are required to create multiple entity records (either by direct
-assertion or by inference), each with its own identifier (so as to allow potential dependencies between the various entity records to be expressed). </li>
+<li>In order to describe something over several intervals, it is required to create multiple entities (either by direct
+assertion or by inference), each with its own identifier (so as to allow potential dependencies between the various entity records).
+
+
+</li>
<li>There is no assumption that the set of attributes is complete and that the attributes are independent or orthogonal of each other.</li>
<li>A characterization interval may collapse into a single instant.</li>
-<li>An entity assertion
- is about a thing, whose situation in the world may be variant.
- An entity record is asserted at a particular point and is invariant, in the sense that
-its attributes are given a value as part of that assertion.
-</li>
-
-
-<li id='attribute-occurrence-in-entity-record'>The attributes
-occurring in an entity record MUST be declared in the namespace
-referred to by their prefix according to
-<a href="#record-attribute">Section record-attribute</a>. Furthermore,
-for each attribute, a namespace also declares the number of
-occurrences it may have in a list of attributes. An entity record is
-valid if the number of occurrences of any of its attributes is
-compatible with this attribute's declaration it its namespace. This
-property applies to all types of records, and is referred to
-as <a>attribute occurrence validity</a>.</li>
-
+
+
+</ul>
@@ -749,44 +728,15 @@
-<p>An activity, represented by an activity record, is delimited by its <a title="activity start event">start</a> and its <a title="activity end event">end</a> events; hence, it occurs over
-an interval delimited by two <a title="event">instantaneous events</a>. However, an activity record need not mention time information, nor duration, because they may not be known.</p>
-
-<p>If start and end times are known, they are expressed as <em>attributes</em> of an activity, where the interpretation of attribute in the context of an activity record is the same as the
-interpretation of attribute for entity record: an activity record's attribute remains constant for the duration of the activity it represents. Further characteristics of the activity in the
-world can be represented by other attribute-value pairs, which MUST also remain unchanged during the activity duration.</p>
-
+<p>An activity is anything that involves entities. An activity is delimited by its <a title="activity start event">start</a> and its <a title="activity end event">end</a> events; hence, it occurs over
+an interval delimited by two <a title="event">instantaneous events</a>. However, an activity need not mention time information, nor duration, because they may not be known.
+An activity's attribute-value pairs remain unchanged during an activity's interval, i.e. an interval between two instantaneous events in the world, namely its <a title="activity start event">start</a> event and its <a title="activity end event">end</a> event.
+</p>
<div class="interpretation-forward">
For the interpretation of an activity record, see <a href="#start-precedes-end">start-precedes-end</a>.
</div>
-<!--
-<p>The mere existence of an activity assertion entails some <a>event</a> ordering in the world, since an <a>activity start event</a> always <a>precedes</a> the corresponding <a>activity end
-event</a>. This is expressed by constraint <a href="#start-precedes-end">start-precedes-end</a>.</p>
-
-<div class='interpretation' id='start-precedes-end'> The following temporal constraint holds for any activity record: the
-<a title="activity start event">start event</a> <a>precedes</a> the <a title="activity end event">end event</a>.</div>
--->
-
-<p>Further considerations:</p>
-<ul>
-<li>The activity identifier <span class="name">id</span> contained in an activity record is also expected to be unique among all the identifiers contained in the current account's records.
-This constraint is elaborated upon in <a href="#identifiable-record-in-account">identifiable-record-in-account</a>. It means that the current account does not contain any other record for
-this identifier, and that effectively <span class="name">id</span> acts as a <em>local</em> identifier for this record in the current account.</li>
-
-<li>An activity record is not an entity record.
-Indeed, an entity record represents an entity that exists in full at
-any point in its characterization interval, persists during this
-interval, and preserves the characteristics that makes it
-identifiable. Alternatively, an activity in something that happens,
-unfolds or develops through time, but is typically not identifiable by
-the characteristics it exhibits at any point during its duration.
-This distinction is similar to the distinction between
-'continuant' and 'occurrent' in logic [[Logic]].</li>
-</ul>
-
-
</section>
<section id="record-Agent">
@@ -1680,7 +1630,38 @@
<section id="structural-constraints">
<h3>PROV-DM Structural Constraints</h3>
-
+<section>
+<h3>Stuff</h3>
+<li>
+The entity identifier <span class="name">id</span> contained in an entity record is expected to be unique among all the identifiers contained in the current account's records.
+This constraint is elaborated upon in <a href="#identifiable-record-in-account">identifiable-record-in-account</a>. It means that the current account does not contain any other record for
+this identifier. Effectively, <span class="name">id</span> acts as a <em>local</em> identifier for this record. In this specification, whenever we write "an entity record identified by ...
+", this identification is to be understood in the context of the account that defines it. </li>
+
+<li>The activity identifier <span class="name">id</span> contained in an activity record is also expected to be unique among all the identifiers contained in the current account's records.
+This constraint is elaborated upon in <a href="#identifiable-record-in-account">identifiable-record-in-account</a>. It means that the current account does not contain any other record for
+this identifier, and that effectively <span class="name">id</span> acts as a <em>local</em> identifier for this record in the current account.</li>
+
+<li>An entity assertion
+ is about a thing, whose situation in the world may be variant.
+ An entity record is asserted at a particular point and is invariant, in the sense that
+its attributes are given a value as part of that assertion.
+</li>
+
+
+<li id='attribute-occurrence-in-entity-record'>The attributes
+occurring in an entity record MUST be declared in the namespace
+referred to by their prefix according to
+<a href="#record-attribute">Section record-attribute</a>. Furthermore,
+for each attribute, a namespace also declares the number of
+occurrences it may have in a list of attributes. An entity record is
+valid if the number of occurrences of any of its attributes is
+compatible with this attribute's declaration it its namespace. This
+property applies to all types of records, and is referred to
+as <a>attribute occurrence validity</a>.</li>
+
+
+</section>
<p>Sections 5 and 6 define a data model for provenance, which, for the most part, is unconstrained. Section 7.1 defines an interpretation of this data model, in terms of event ordering
constraints. This section introduces further constraints on the structure of PROV-DM records. Records that satisfy these constraints are said to be <dfn>structurally well-formed</dfn>. A