--- a/model/ProvenanceModel.html Wed Sep 07 18:47:47 2011 -0400
+++ b/model/ProvenanceModel.html Thu Sep 08 11:32:21 2011 +0100
@@ -25,6 +25,13 @@
"<a href=\"http://www.w3.org/2011/prov/wiki/FormalSemanticsStrawman\"><cite>Formal Semantics Strawman</cite></a>. "+
"2011, Work in progress. "+
"URL: <a href=\"http://www.w3.org/2011/prov/wiki/FormalSemanticsStrawman\">http://www.w3.org/2011/prov/wiki/FormalSemanticsStrawman</a>",
+
+ "PROV-PRIMER":
+ "Simon Miles "+
+ "<a href=\"http://www.w3.org/2011/prov/wiki/ProvenancePrimer\"><cite>Provenance Primer</cite></a>. "+
+ "2011, Work in progress. "+
+ "URL: <a href=\"http://www.w3.org/2011/prov/wiki/ProvenancePrimer\">http://www.w3.org/2011/prov/wiki/ProvenancePrimer</a>",
+
"PROV-OWL2":
"Satya Sahoo and Deborah McGuinness "+
"<a href=\"http://dvcs.w3.org/hg/prov/raw-file/default/ontology/ProvenanceFormalModel.html\"><cite>Provenance Formal Model</cite></a>. "+
@@ -167,6 +174,8 @@
<p>In our conceptualization of the world, punctual events, or <dfn id="concept-event">events</dfn> for short, happen in the world, which mark changes in the world, in its activities, and in its things. In this specification, it is assumed that a partial order exists between events. How practically such order is realized is beyond the scope of this specification. Possible implementations of that ordering include a single global notion of time and Lamport's style clocks.</p>
+
+<p> In this specification, the qualifier 'identifiable' is implicit whenever a reference is made to an activity or characterized thing.</p>
</section>
<section>
@@ -206,9 +215,22 @@
<p>
PIDM is a provenance data model designed to express <em>representations</em> of the world.
+</p>
+
+<div class="xmpl">
+A file at some point during its lifecycle, which includes multiple edits by multiple people, can be represented by its location in the file system, a creator, and content.
+</div>
+
+
+<p>
These representations are relative to an asserter, and in that sense constitute assertions stating properties of the world, as represented by an asserter. Different asserters will normally contribute different representations, and no attempt is made to define a notion of consistency of such different sets of assertions. The data model provides the means to associate attribution to assertions.
</p>
+<div class="xmpl">
+An alternative representation of the above file is a set of blocks in a hard disk.
+</div>
+
+
<p>The data model is designed to capture events that happened in the past, as opposed to event
that may or will happen.
However, this distinction is not formally enforced.
@@ -253,6 +275,9 @@
<section class="informative">
<h2>Example</h2>
+To illustrate PIDM, this section presents an example encoded according to the Provenance Abstract Syntax Notation. For more detailed explanations of how PIDM should be used, and for more examples, we refer the reader to the Provenance Primer [[PROV-PRIMER]].
+
+
<div class='pending'>Alter example to cater for multiple ivpOf. This is <a href="http://www.w3.org/2011/prov/track/issues/33">ISSUE-33</a>.</div>
@@ -446,50 +471,8 @@
</section>
- <section >
-<h2>About the Provenance Data Model</h2>
-
-
-<div class='note'>This section is now obsolete and should be deleted. We need to check that the following text has been captured elsewhere.</div>
-
-
-
-<p>
-In the rest of the document, we are concerned with the representation of such things; their situation in the world will be represented using sets of attributes.
-</p>
-
-<p>
-<div class="example">
-<b>Example</b>: a file at some point during its lifecycle, which includes multiple edits by multiple people, can be represented by its location in the file system, a creator, and content.
-</div>
-</p>
-
-
-
-
-
-<p>The data model includes a notion of "provenance container" that is
- a logical grouping for a set of assertions. It serves multiple
- purposes. First, it provides a way to attach various metadata to the
- set of assertions. Second, it provides a scope in which some constraints may apply.
- Third, it provides a default scope for
- identifiers used in assertions. This means that identifiers are
- expected to be resolvable only within the scope of a container,
- rather than globally. Optionally, identifiers can be exported so that
- they can be used outside their default scope. Finally, the data
- model does not prescribe the mechanisms by which identifiers are
- generated.</p>
-
-
-
-
-<p> In this specification, the qualifier 'identifiable' is implicit whenever a reference is made to an activity or characterized thing.</p>
-
- </section>
-
-
-
- <section id="data-model-concepts">
+
+<section id="data-model-concepts">
<h2>Provenance Data Model</h2>
@@ -1221,27 +1204,47 @@
<h3>Complementarity</h3>
-<p><dfn id="IVP-of">Is Complement Of</dfn> is a relationship between two characterized things asserted to have compatible characterization over some continuous time interval.<br/>
-
-The rationale for introducing this relationship is that in general, at any given time there will be multiple representations of a characterized thing, which are reflected in assertions possibly made by different asserters. In the example that follows, suppose thing "Royal Society" is represented by two asserters, each using a different set of attributes. If the asserters agree that both representations refer to "The Royal Society", the question of whether any correspondence can be established between the two representations arises naturally. This is particularly relevant when (a) the sets of properties used by the two representations overlap partially, or (b) when one set is subsumed by the other. In both these cases, we have a situation where each of the two asserters has a partial view of "The Royal Society", and establishing a correspondence between them on the shared properties is beneficial, as in case (a) each of the two representation <em>complements</em> the other, and in case (b) one of the two (that with the additional properties) complements the other.
-<p/>
-This intuition is made more precise by considering the entities that embody the representation of a characterised thing at a certain point in time. an entity, as defined above, exists only as long as all of its attributes do not change their value. As soon as one attribute, say X changes value, say from v1 to v2, the entity no longer exists and is replaced by a new one in which X=v2. Thus, if we overlap the timelines (or, more generally, the sequences of value-changing events) for the two characterised things, we can hope two establish correspondences amongst the entities that represent them at various points along that events line. The figure below illustrates this intuition.<p/>
+<p>A <dfn id="complementOf">complementarity expression</dfn> is a relationship between two characterized things stated to have compatible characterization over some continuous interval between two events.</p>
+
+
+<p>
+The rationale for introducing this relationship is that in general, at any given time, for a thing in the world, there may be multiple way of characterizing it, and hence multiple representations can be asserted by different asserters. In the example that follows, suppose thing "Royal Society" is represented by two asserters, each using a different set of attributes. If the asserters agree that both representations refer to "The Royal Society", the question of whether any correspondence can be established between the two representations arises naturally. This is particularly relevant when (a) the sets of properties used by the two representations overlap partially, or (b) when one set is subsumed by the other. In both these cases, we have a situation where each of the two asserters has a partial view of "The Royal Society", and establishing a correspondence between them on the shared properties is beneficial, as in case (a) each of the two representation <em>complements</em> the other, and in case (b) one of the two (that with the additional properties) complements the other.</p>
+
+<p>This intuition is made more precise by considering the entities that form the representations of characterised things at a certain point in time.
+
+An entity represents, by means of attribute-value pairs, a thing and its situation in the world, which remain constant over a characterization interval.
+As soon as the thing's situation changes, this marks the end of the characterization interval for the entity representing it. The thing's novel situation is represented by an attribute with a new value, or an entirely different set of attribute-value pairs, embodied in another entity, with a new characterization interval. Thus, if we overlap the timelines (or, more generally, the sequences of value-changing events) for the two characterised things, we can hope two establish correspondences amongst the entities that represent them at various points along that events line. The figure below illustrates this intuition.</p>
<img src="complement-of.png"/>
-<p/>
-Relation <em>complement-of</em> between two entities is intended to capture these correspondences, as follows. Suppose entities A and B share a set P of properties, and each of them has other properties in addition to P. If the values assigned to each property in P are <em>compatible</em> between A and B, then we say that <em>A is-complement-of B</em>, and <em>B is-complement-of A</em>, in a symmetrical fashion. In the particular case where the set P of properties of B is a struct superset of A's properties, then we say that <em>B is-complement-of A</em>, but in this case the opposite does not hold. In this case, the relation is not symmetric. (as a special case, A and B may not share any attributes at all, and yet the asserters may still stipulate that they are representing the same thing "Royal Society". The symmetric relation may hold trivially in this case).
-<p/>
-The term <em>compatible</em> used above means that a mapping can be established amongst the values of attributes in P and found in the two entities. This is generalizes to the case where attribute sets P1 and P2 of A, and B, respectively, are not identical but they can be mapped to one another. The simplest case is the identity mapping, in which A and B share attribute set P, and furthermore the values assigned to attributes in P match exactly.<br/>
-
-It is important to note that the relation holds only as long as the entities involved are valid. As soon as one attribute changes value in one of them, new correspondences need to be found amongst the new entities. Thus, the relation has a validity span that can be expressed in terms of the event lines of the thing.
+<p>
+Relation <em>complement-of</em> between two entities is intended to capture these correspondences, as follows. Suppose entities A and B share a set P of properties, and each of them has other properties in addition to P. If the values assigned to each property in P are <em>compatible</em> between A and B, then we say that <em>A is-complement-of B</em>, and <em>B is-complement-of A</em>, in a symmetrical fashion. In the particular case where the set P of properties of B is a struct superset of A's properties, then we say that <em>B is-complement-of A</em>, but in this case the opposite does not hold. In this case, the relation is not symmetric. (as a special case, A and B may not share any attributes at all, and yet the asserters may still stipulate that they are representing the same thing "Royal Society". The symmetric relation may hold trivially in this case).</p>
+
+<p>The term <em>compatible</em> used above means that a mapping can be established amongst the values of attributes in P and found in the two entities. This is generalizes to the case where attribute sets P1 and P2 of A, and B, respectively, are not identical but they can be mapped to one another. The simplest case is the identity mapping, in which A and B share attribute set P, and furthermore the values assigned to attributes in P match exactly.</p>
+
+<p>It is important to note that the relation holds only as long as the entities involved are valid. As soon as one attribute changes value in one of them, new correspondences need to be found amongst the new entities. Thus, the relation has a validity span that can be expressed in terms of the event lines of the thing.</p>
<!--
The "IVP of" relationship is designed to represent pairs of entities that correspond to each other. By their own nature, an entity remains valid only as long as all of its attributes do not change their value. It follows that the correspondence "B IVP of A" is only valid within the time interval during which such invariance property holds for both A and B. When any of the property values change in either A or B, those entities are replaced by new ones, and a new correspondence may be established. Thus, "IVP of" is defined relative to the intersection of the temporal intervals for which A and B are valid.
-->
-</p>
-
-<p>An wasComplementOf assertion is denoted <span class="name">wasComplementOf(B,A)</span>, where A and B are two entities.
+
+
+
+<p>In the Provenance Abstract Syntax Notation, a complementarity expression's text matches the <span class="nonterminal">complementarity</span> production of the grammar defined in this specification document.</p>
+
+<div class='grammar'>
+<span class="nonterminal">complementarity</span> :=
+<span class="name">wasComplementOf</span>
+<span class="name">(</span>
+<span class="nonterminal">identifier</span>
+<span class="name">,</span>
+<span class="nonterminal">identifier</span>
+<span class="name">)</span>
+</div>
+
+
+
+<p>An instance of a complementarity expression, written <span class="name">wasComplementOf(e2,e1)</span>, where <span class="name">e1</span> and <span class="name">e2</span> are two identifiers denoting entities.</p>
<p>
<pre class="example">