--- a/model/prov-dm.html Tue Mar 27 23:02:31 2012 +0100
+++ b/model/prov-dm.html Tue Mar 27 23:25:44 2012 +0100
@@ -1105,8 +1105,8 @@
<p><div class="attributes" id="attributes-activity"> An <dfn title="dfn-Activity">activity</dfn><span class="withPn">, written <span class="pnExpression" id="pn-activity">activity(id, st, et, [ attr1=val1, ...])</span> in PROV-N,</span> contains:
<ul>
<li><span class='attribute' id="activity.id">id</span>: an identifier for an activity;</li>
-<li><span class='attribute' id="activity.startTime">startTime</span>: an OPTIONAL time for the start of the activity;</li>
-<li><span class='attribute' id="activity.endTime">endTime</span>: an OPTIONAL time for the end of the activity;</li>
+<li><span class='attribute' id="activity.startTime">startTime</span>: an OPTIONAL time (<span class="name">st</span>) for the start of the activity;</li>
+<li><span class='attribute' id="activity.endTime">endTime</span>: an OPTIONAL time (<span class="name">et</span>) for the end of the activity;</li>
<li><span class='attribute' id="activity.attributes">attributes</span>: an OPTIONAL set of attribute-value pairs for this activity.</li>
</ul></div>
@@ -1143,12 +1143,12 @@
<div class="attributes" id="attributes-generation"><dfn title="dfn-Generation">Generation</dfn><span class="withPn">, written <span class="pnExpression">wasGeneratedBy(id,e,a,t,attrs)</span> in PROV-N,</span> has the following components:
<ul>
<li><span class='attribute' id="generation.id">id</span>: an OPTIONAL identifier for a generation;</li>
-<li><span class='attribute' id="generation.entity">entity</span>: an identifier for a created entity; </li>
-<li><span class='attribute' id="generation.activity">activity</span>: an OPTIONAL identifier for the activity that creates the entity;</li>
-
-<li><span class='attribute' id="generation.time">time</span>: an OPTIONAL "generation time", the time at which the entity was completely created;</li>
-
-<li><span class='attribute' id="generation.attributes">attributes</span>: an OPTIONAL set of attribute-value pairs that describes the modalities of generation of this entity by this activity.</li>
+<li><span class='attribute' id="generation.entity">entity</span>: an identifier (<span class="name">e</span>) for a created entity; </li>
+<li><span class='attribute' id="generation.activity">activity</span>: an OPTIONAL identifier (<span class="name">a</span>) for the activity that creates the entity;</li>
+
+<li><span class='attribute' id="generation.time">time</span>: an OPTIONAL "generation time" (<span class="name">t</span>), the time at which the entity was completely created;</li>
+
+<li><span class='attribute' id="generation.attributes">attributes</span>: an OPTIONAL set (<span class="name">attrs</span>) of attribute-value pairs that describes the modalities of generation of this entity by this activity.</li>
</ul></div>
<p>While each of the components <span class='attribute'>activity</span>, <span class='attribute'>time</span>, and <span class='attribute'>attributes</span> is OPTIONAL, at least one of them MUST be present.</p>
@@ -1192,10 +1192,10 @@
<p><div class="attributes" id="attributes-usage"><dfn title="used">Usage</dfn><span class="withPn">, written <span class="pnExpression">used(id,a,e,t,attrs)</span> in PROV-N,</span> has the following constituents:
<ul>
<li><span class='attribute' id="usage.id">id</span>: an OPTIONAL identifier for a usage;</li>
-<li><span class='attribute' id="usage.activity">activity</span>: an identifier for the consuming activity;</li>
-<li><span class='attribute' id="usage.entity">entity</span>: an identifier for the consumed entity;</li>
-<li><span class='attribute' id="usage.time">time</span>: an OPTIONAL "usage time", the time at which the entity started to be used;</li>
-<li><span class='attribute' id="usage.attributes">attributes</span>: an OPTIONAL set of attribute-value pairs that describe the modalities of usage of this entity by this activity.</li>
+<li><span class='attribute' id="usage.activity">activity</span>: an identifier (<span class="name">a</span>) for the consuming activity;</li>
+<li><span class='attribute' id="usage.entity">entity</span>: an identifier (<span class="name">e</span>) for the consumed entity;</li>
+<li><span class='attribute' id="usage.time">time</span>: an OPTIONAL "usage time" (<span class="name">t</span>), the time at which the entity started to be used;</li>
+<li><span class='attribute' id="usage.attributes">attributes</span>: an OPTIONAL set (<span class="name">attrs</span>) of attribute-value pairs that describe the modalities of usage of this entity by this activity.</li>
</ul></div>
<p>
@@ -1242,10 +1242,10 @@
<p>An activity <dfn title="wasStartedBy">start</dfn><span class="withPn">, written <span class="pnExpression">wasStartedBy(id,a,e,t,attrs)</span> in PROV-N,</span> contains:</p>
<ul>
<li><span class='attribute' id="start.id">id</span>: an OPTIONAL identifier for the activity start;</li>
-<li><span class='attribute' id="start.activity">activity</span>: an identifier for the started activity;</li>
-<li><span class='attribute' id="start.trigger">trigger</span>: an OPTIONAL identifier for the entity triggering the activity;</li>
-<li><span class='attribute' id="start.time">time</span>: the OPTIONAL time at which the activity was started; </li>
-<li><span class='attribute' id="start.attributes">attributes</span>: an OPTIONAL set of attribute-value pairs describing modalities according to which the activity was started.
+<li><span class='attribute' id="start.activity">activity</span>: an identifier (<span class="name">a</span>) for the started activity;</li>
+<li><span class='attribute' id="start.trigger">trigger</span>: an OPTIONAL identifier (<span class="name">e</span>) for the entity triggering the activity;</li>
+<li><span class='attribute' id="start.time">time</span>: the OPTIONAL time (<span class="name">t</span>) at which the activity was started; </li>
+<li><span class='attribute' id="start.attributes">attributes</span>: an OPTIONAL set (<span class="name">attrs</span>) of attribute-value pairs describing modalities according to which the activity was started.
</ul>
<div class="anexample">
@@ -1286,13 +1286,13 @@
<div class="glossary-ref" ref="glossary-end"></div>
-<p>An activity <dfn title="wasEndedBy">end</dfn><span class="withAsn">, written <span class="pnExpression">wasEndedBy(id,a,e,t,attrs)</span> in PROV-ASN,</span> contains:</p>
+<p>An activity <dfn title="wasEndedBy">end</dfn><span class="withAsn">, written <span class="pnExpression">wasEndedBy(id,a,e,t,attrs)</span> in PROV-N,</span> contains:</p>
<ul>
<li><span class='attribute' id="end.id">id</span>: an OPTIONAL identifier for the activity end;</li>
-<li><span class='attribute' id="end.activity">activity</span>: an identifier for the ended activity;
-<li><span class='attribute' id="end.trigger">trigger</span>: an OPTIONAL identifier for the entity triggering the activity ending;
-<li><span class='attribute' id="end.time">time</span>: the OPTIONAL time at which the activity was ended; </li>
-<li><span class='attribute' id="end.attributes">attributes</span>: an OPTIONAL set of attribute-value pairs describing modalities according to which the activity was ended.
+<li><span class='attribute' id="end.activity">activity</span>: an identifier (<span class="name">a</span>) for the ended activity;
+<li><span class='attribute' id="end.trigger">trigger</span>: an OPTIONAL identifier (<span class="name">e</span>) for the entity triggering the activity ending;
+<li><span class='attribute' id="end.time">time</span>: the OPTIONAL time (<span class="name">t</span>) at which the activity was ended; </li>
+<li><span class='attribute' id="end.attributes">attributes</span>: an OPTIONAL set (<span class="name">attrs</span>) of attribute-value pairs describing modalities according to which the activity was ended.
</ul>
<div class="anexample">
@@ -1329,9 +1329,9 @@
<span class="pnExpression">wasInformedBy(id,a2,a1,attrs)</span> in PROV-N,</span> contains:
<ul>
<li><span class='attribute'>id</span>: an OPTIONAL identifier identifying the relation;</li>
-<li><span class='attribute'>informed</span>: the identifier of the informed activity;
-<li><span class='attribute'>informant</span>: the identifier of the informant activity;
-<li><span class='attribute'>attributes</span>: an OPTIONAL set of attribute-value pairs to further describe properties of the relation.</li>
+<li><span class='attribute'>informed</span>: the identifier (<span class="name">a2</span>) of the informed activity;
+<li><span class='attribute'>informant</span>: the identifier (<span class="name">a1</span>) of the informant activity;
+<li><span class='attribute'>attributes</span>: an OPTIONAL set (<span class="name">attrs</span>) of attribute-value pairs to further describe properties of the relation.</li>
</ul>
</div>
@@ -1362,9 +1362,9 @@
<span class="pnExpression">wasStartedByActivity(id, a2, a1, attrs)</span> in PROV-N,</span> contains: </p>
<ul>
<li><span class='attribute' id="startByActivity.id">id</span>: an OPTIONAL identifier of the relation;</li>
-<li><span class='attribute' id="startByActivity.started">started</span>: the identifier of the started activity;
-<li><span class='attribute' id="startByActivity.starter">starter</span>: the identifier of the activity that started the other;</li>
-<li><span class='attribute' id="startByActivity.attributes">attributes</span>: an OPTIONAL set of attribute-value pairs to further describe the properties of the relation.</li>
+<li><span class='attribute' id="startByActivity.started">started</span>: the identifier (<span class="name">a2</span>) of the started activity;
+<li><span class='attribute' id="startByActivity.starter">starter</span>: the identifier (<span class="name">a1</span>) of the activity that started the other;</li>
+<li><span class='attribute' id="startByActivity.attributes">attributes</span>: an OPTIONAL set (<span class="name">attrs</span>) of attribute-value pairs to further describe the properties of the relation.</li>
</ul>
</div>
@@ -1409,8 +1409,8 @@
<p><div class="attributes" id="attributes-agent">An <dfn title="dfn-agent">agent</dfn><span class="withPn">, noted <span class="pnExpression" id="pn-agent">agent(id, [ attr1=val1, ...])</span> in PROV-N,</span> contains:
<ul>
-<li><span class='attribute' id="agent.id>id</span>: an identifier for an agent;</li>
-<li><span class='attribute' id="agent.attributes>attributes</span>: a set of attribute-value pairs representing this agent's situation in the world.
+<li><span class='attribute' id="agent.id">id</span>: an identifier for an agent;</li>
+<li><span class='attribute' id="agent.attributes">attributes</span>: a set of attribute-value pairs representing this agent's situation in the world.
</li>
</ul></div>
@@ -1446,12 +1446,12 @@
<p>When an entity <span class="name">e</span> is attributed to agent <span class="name">ag</span>, entity <span class="name">e</span> was generated by some activity <span class="name">a</span>, which in turn was associated to agent <span class="name">ag</span>. Thus, this relation is useful when the activity is not known, or irrelevant.</p>
-<p> An <dfn title="wasAttributedTo">attribution relation</dfn><span class="withPn">, written <span class="pnExpression">wasAttributedTo(id,e,ag,attr)</span> in PROV-N,</span> contains the following elements:</p>
+<p> An <dfn title="wasAttributedTo">attribution relation</dfn><span class="withPn">, written <span class="pnExpression">wasAttributedTo(id,e,ag,attrs)</span> in PROV-N,</span> contains the following elements:</p>
<ul>
-<li><span class='attribute' id="attribution.id>id</span>: an OPTIONAL identifier for the relation;</li>
-<li><span class='attribute' id="attribution.entity>entity</span>: an entity identifier;</li>
-<li><span class='attribute' id="attribution.agent>agent</span>: the identifier of the agent whom the entity is ascribed to;</li>
-<li><span class='attribute' id="attribution.attributes>attributes</span>: an OPTIONAL set of attribute-value pairs to further describe the properties of the relation.</li>
+<li><span class='attribute' id="attribution.id">id</span>: an OPTIONAL identifier for the relation;</li>
+<li><span class='attribute' id="attribution.entity">entity</span>: an entity identifier (<span class="name">e</span>);</li>
+<li><span class='attribute' id="attribution.agent">agent</span>: the identifier (<span class="name">ag</span>) of the agent whom the entity is ascribed to;</li>
+<li><span class='attribute' id="attribution.attributes">attributes</span>: an OPTIONAL set (<span class="name">attrs</span>) of attribute-value pairs to further describe the properties of the relation.</li>
</ul>
<div class="anexample">
@@ -1480,10 +1480,10 @@
constituents:
<ul>
<li><span class='attribute' id="association.id">id</span>: an OPTIONAL identifier for the association between an activity and an agent;</li>
-<li><span class='attribute' id="association.activity">activity</span>: an identifier for the activity;</li>
-<li><span class='attribute' id="association.agent">agent</span>: an OPTIONAL identifier for the agent associated with the activity;</li>
-<li><span class='attribute' id="association.plan">plan</span>: an OPTIONAL identifier for the plan adopted by the agent in the context of this activity;
-<li><span class='attribute' id="association.attributes">attributes</span>: an OPTIONAL set of attribute-value pairs that describe the modalities of association of this activity with this agent.</li>
+<li><span class='attribute' id="association.activity">activity</span>: an identifier (<span class="name">a</span>) for the activity;</li>
+<li><span class='attribute' id="association.agent">agent</span>: an OPTIONAL identifier (<span class="name">ag</span>) for the agent associated with the activity;</li>
+<li><span class='attribute' id="association.plan">plan</span>: an OPTIONAL identifier (<span class="name">pl</span>) for the plan adopted by the agent in the context of this activity;
+<li><span class='attribute' id="association.attributes">attributes</span>: an OPTIONAL set (<span class="name">attrs</span>) of attribute-value pairs that describe the modalities of association of this activity with this agent.</li>
</ul></div>
<div class="anexample" id="anexample-wasAssociateWith">
@@ -1556,11 +1556,11 @@
<p><div class="attributes" id="attributes-responsibility-chain">A <dfn title="actedOnBehalfOf">responsibility</dfn> relation<span class="withPn">, written <span class="pnExpression">actedOnBehalfOf(id,ag2,ag1,a,attrs)</span> in PROV-N,</span> has the following constituents:
<ul>
<li><span class='attribute' id="responsibility.id">id</span>: an OPTIONAL identifier for the responsibility chain;</li>
-<li><span class='attribute' id="responsibility.subordinate">subordinate</span>: an identifier for the agent associated with an activity, acting on behalf of the responsible
+<li><span class='attribute' id="responsibility.subordinate">subordinate</span>: an identifier (<span class="name">ag2</span>) for the agent associated with an activity, acting on behalf of the responsible
agent;</li>
-<li><span class='attribute' id="responsibility.responsible">responsible</span>: an identifier for the agent, on behalf of which the subordinate agent acted;</li>
-<li><span class='attribute' id="responsibility.activity">activity</span>: an OPTIONAL identifier of an activity for which the responsibility chain holds;</li>
-<li><span class='attribute' id="responsibility.attributes">attributes</span>: an OPTIONAL set of attribute-value pairs that describe the modalities of this relation.</li>
+<li><span class='attribute' id="responsibility.responsible">responsible</span>: an identifier (<span class="name">ag1</span>) for the agent, on behalf of which the subordinate agent acted;</li>
+<li><span class='attribute' id="responsibility.activity">activity</span>: an OPTIONAL identifier (<span class="name">a</span>) of an activity for which the responsibility chain holds;</li>
+<li><span class='attribute' id="responsibility.attributes">attributes</span>: an OPTIONAL set (<span class="name">attrs</span>) of attribute-value pairs that describe the modalities of this relation.</li>
</ul></div>
@@ -1621,7 +1621,7 @@
-<p>According to <a href="#conceptualization">Section Overview</a>, for an entity to be transformed from, created from, or resulting from an update to another, there must be some
+<p>According to <a href="#starting-points">Section Starting Points</a>, for an entity to be transformed from, created from, or resulting from an update to another, there must be some
underpinning activities performing the necessary actions resulting in such a derivation.
A derivation can be described at various levels of precision. In its simplest form, derivation relates two entities. Optionally, attributes can be added to describe modalities of derivation. If the derivation is the result of a single known activity, then this activity can also be optionally expressed. And to provide a completely accurate description of derivation, the generation and usage of the generated and used entities, respectively, can be provided. The reason for optional information such as activity, generation, and usage to be linked to derivations is to aid analysis of provenance and to facilitate provenance-based reproducibility. </p>
@@ -1629,12 +1629,12 @@
<p><div class="attributes" id="attributes-derivation">A <dfn title="wasDerivedFrom">derivation</dfn><span class="withPn">, written <span class="pnExpression" id="pn-wasDerivedFrom">wasDerivedFrom(id, e2, e1, a, g2, u1, attrs)</span> in PROV-N,</span> contains:
<ul>
<li><span class='attribute' id="derivation.id">id</span>: an OPTIONAL identifier for a derivation;</li>
-<li><span class='attribute' id="derivation.generatedEntity">generatedEntity</span>: the identifier of the entity generated by the derivation;</li>
-<li><span class='attribute' id="derivation.usedEntity">usedEntity</span>: the identifier of the entity used by the derivation;</li>
-<li><span class='attribute' id="derivation.activity">activity</span>: an OPTIONAL identifier for the activity using and generating the above entities;</li>
-<li><span class='attribute' id="derivation.generation">generation</span>: an OPTIONAL identifier for the generation involving the generated entity and activity;</li>
-<li><span class='attribute' id="derivation.usage">usage</span>: an OPTIONAL identifier for the usage involving the used entity and activity;</li>
-<li><span class='attribute' id="derivation.attributes">attributes</span>: an OPTIONAL set of attribute-value pairs that describe the modalities of this derivation.</li>
+<li><span class='attribute' id="derivation.generatedEntity">generatedEntity</span>: the identifier (<span class="name">ee</span>) of the entity generated by the derivation;</li>
+<li><span class='attribute' id="derivation.usedEntity">usedEntity</span>: the identifier (<span class="name">e1</span>) of the entity used by the derivation;</li>
+<li><span class='attribute' id="derivation.activity">activity</span>: an OPTIONAL identifier (<span class="name">a</span>) for the activity using and generating the above entities;</li>
+<li><span class='attribute' id="derivation.generation">generation</span>: an OPTIONAL identifier (<span class="name">g2</span>) for the generation involving the generated entity and activity;</li>
+<li><span class='attribute' id="derivation.usage">usage</span>: an OPTIONAL identifier (<span class="name">u1</span>) for the usage involving the used entity and activity;</li>
+<li><span class='attribute' id="derivation.attributes">attributes</span>: an OPTIONAL set (<span class="name">attrs</span>) of attribute-value pairs that describe the modalities of this derivation.</li>
</ul>
</div>
@@ -1683,10 +1683,10 @@
<p> A <dfn title="wasRevisionOf">revision</dfn> relation<span class="withPn">, written <span class="pnExpression">wasRevisionOf(id,e2,e1,ag,attrs)</span> in PROV-N,</span> contains:</p>
<ul>
<li><span class='attribute' id="revision.id">id</span>: an OPTIONAL identifier for the relation;</li>
-<li><span class='attribute' id="revision.newer">newer</span>: the identifier of the revised entity;
-<li><span class='attribute' id="revision.older">older</span>: the identifier of the older entity;
-<li><span class='attribute' id="revision.responsibility">responsibility</span>: an OPTIONAL identifier for the agent who approved the newer entity as a variant of the older;
-<li><span class='attribute' id="revision.attributes">attributes</span>: an OPTIONAL set of attribute-value pairs to further describe the properties of this relation.</li>
+<li><span class='attribute' id="revision.newer">newer</span>: the identifier (<span class="name">e2</span>) of the revised entity;
+<li><span class='attribute' id="revision.older">older</span>: the identifier (<span class="name">e1</span>) of the older entity;
+<li><span class='attribute' id="revision.responsibility">responsibility</span>: an OPTIONAL identifier (<span class="name">ag</span>) for the agent who approved the newer entity as a variant of the older;
+<li><span class='attribute' id="revision.attributes">attributes</span>: an OPTIONAL set (<span class="name">attrs</span>) of attribute-value pairs to further describe the properties of this relation.</li>
</ul>
@@ -1725,7 +1725,7 @@
<li><span class='attribute' id="quotation.original">original</span>: an identifier (<span class="name">e1</span>) for the original entity being quoted;
<li><span class='attribute' id="quotation.quoterAgent">quoterAgent</span>: an OPTIONAL identifier (<span class="name">ag2</span>) for the agent who performs the quote;
<li><span class='attribute' id="quotation.originalAgent">originalAgent</span>: an OPTIONAL identifier (<span class="name">ag1</span>) for the agent to whom the original entity is attributed;
-<li><span class='attribute' id="quotation.attributes">attributes</span>: an OPTIONAL set of attribute-value pairs to further describe the properties of the relation.</li>
+<li><span class='attribute' id="quotation.attributes">attributes</span>: an OPTIONAL set (<span class="name">attrs</span>) of attribute-value pairs to further describe the properties of the relation.</li>
</ul>
@@ -1769,9 +1769,9 @@
<p> An <dfn title="hadOriginalSource">original source</dfn> relation<span class="withPn">, written <span class="pnExpression">hadOriginalSource(id,e2,e1,attrs)</span>,</span> contains:</p>
<ul>
<li><span class='attribute' id="originalSource.id">id</span>: an OPTIONAL identifier for the relation;</li>
-<li><span class='attribute' id="originalSource.derived">derived</span>: an identifier for the derived entity; </li>
-<li><span class='attribute' id="originalSource.source">source</span>: an identifier for the original source entity;</li>
-<li><span class='attribute' id="originalSource.attributes">attributes</span>: an OPTIONAL set of attribute-value pairs to further describe the properties of the relation.</li>
+<li><span class='attribute' id="originalSource.derived">derived</span>: an identifier (<span class="name">e2</span>) for the derived entity; </li>
+<li><span class='attribute' id="originalSource.source">source</span>: an identifier (<span class="name">e1</span>) for the original source entity;</li>
+<li><span class='attribute' id="originalSource.attributes">attributes</span>: an OPTIONAL set (<span class="name">attrs</span>) of attribute-value pairs to further describe the properties of the relation.</li>
</ul>
<div class="anexample">
@@ -1804,9 +1804,9 @@
<p><dfn title="tracedTo">Traceability</dfn><span class="withPn">, written <span class="pnExpression">tracedTo(id,e2,e1,attrs)</span> in PROV-N,</span> contains:</p>
<ul>
<li><span class='attribute' id="traceability.id">id</span>: an OPTIONAL identifier identifying the relation;</li>
-<li><span class='attribute' id="traceability.entity">entity</span>: an identifier identifying an entity;
-<li><span class='attribute' id="traceability.ancestor">ancestor</span>: an identifier identifying an ancestor entity that the former depends on;
-<li><span class='attribute' id="traceability.attributes">attributes</span>: an OPTIONAL set of attribute-value pairs to further describe properties of the relation.</li>
+<li><span class='attribute' id="traceability.entity">entity</span>: an identifier (<span class="name">e2</span>) for an entity;
+<li><span class='attribute' id="traceability.ancestor">ancestor</span>: an identifier (<span class="name">e1</span>) for an ancestor entity that the former depends on;
+<li><span class='attribute' id="traceability.attributes">attributes</span>: an OPTIONAL set (<span class="name">attrs</span>) of attribute-value pairs to further describe properties of the relation.</li>
</ul>
<p>We note that the ancestor is allowed to be an agent since agents are entities. </p>
@@ -1835,8 +1835,10 @@
<h3>Component 4: Alternate Entities</h3>
-<p>The fourth component of PROV-DM is concerned with relations <a>alternate</a> and <a>specialization</a> between entities.
-Figure <a href="#figure-component4">figure-component4</a> overviews the component.
+<p>The fourth component of PROV-DM is concerned with
+relations <a>specialization</a> and <a>alternate</a> between entities.
+Figure <a href="#figure-component4">figure-component4</a> overviews
+the component.
</p>
@@ -1848,103 +1850,114 @@
</div>
-<p>This component consists of relations between two entities that refer to the same thing
-Consider for example three entities:
-</p>
-<ul>
- <li><span class="name">e1</span> denoting "Bob, the holder of Facebook account ABC",
-
- <li><span class="name">e2</span> denoting "Bob, the holder of Twitter account XYZ",
-
- <li><span class="name">e3</span> denoting "Bob, the person".
-</ul>
-
-<p>These entities refer to the same real person Bob, either in different contexts, or at different levels of abstraction. Specifically:
-
-
-<ol>
- <li><span class="name">e1</span> and <span class="name">e2</span> refer to Bob in two contexts (as Facebook and Twitter users, respectively)
- <li> both of <span class="name">e1</span> and <span class="name">e2</span> are more detailed than <span class="name">e3</span>.
-</ol>
-
-
-
-
-
-<p>The following two relations are introduced for expressing alternative or specialized entities. </p>
-
-<section id="term-alternate">
-
-<h4>Alternate</h4>
-
-<div class="note">To define</div>
-
-
-<span class="glossary" id="glossary-alternate">
-An entity is <dfn id="concept-alternate">alternate</dfn> of another if they refer to a same thing.
-</span>
-
-
-
-
-<p><div class="attributes" id="attributes-alternate">An <dfn title="alternateOf">alternate relation</dfn><span class="withPn">, written <span class="pnExpression">alternateOf(alt1, alt2)</span> in PROV-N,</span> addresses case (1). It has the following constituents:
-<ul>
-<li><span class='attribute' id="alternate.firstAlternate">firstAlternate</span>: an identifier of the first of the two entities;</li>
-<li><span class='attribute' id="alternate.secondAlternate">secondAlternate</span>: an identifier of the second of the two entities.</li>
-</ul>
+
+<p>Wherever two people describe the provenance of a same thing,
+one cannot expect them to coordinate and agree on the identifiers to use to denote that thing.</p>
+<div class="anexample" id="entity-example">
+<p>User Alice writes an article. In its provenance, she wishes to refer to the precise version of the article with a date-specific URI, as she might edit the article later. Alternatively, user Bob refers to the article in general, indepedently of its variants over time.</p>
</div>
-
-<div class="anexample" id="anexample-alternate">
-<p>The following expressions describe two persons, respectively holder of a Facebook account and a Twitter account, and their relation as alternate. </p>
-<pre class="codeexample">
-entity(facebook:ABC, [ prov:type="person with Facebook account " ])
-entity(twitter:XYZ, [ prov:type="person with Twitter account" ])
-alternateOf(facebook:ABC, twitter:XYZ)
-</pre>
-</div>
-
-</section>
+<p>
+To allow for identifiers to be chosen freely and independently by each user, the PROV data model introduces relations
+that allow entities to be linked together.
+The following two relations are introduced for expressing specialized or alternate entities. </p>
+
<section id="term-specialization">
<h4>Specialization</h4>
-<div class="note">To define</div>
<span class="glossary" id="glossary-specialization">
-An entity is a <dfn id="concept-alternate">specialization</dfn> of another if the latter is a more
-general entity than the former.
-</span>
+An entity is a <dfn id="concept-alternate">specialization</dfn> of another if they both refer to some common thing
+but the former is a more constrained entity than the former. The common entity does not need to be identified.
+</span>
+Examples of constraints include a time period, an abstraction, and a context associated with the entity.
+
+
<p>
-<div class="attributes" id="attributes-specialization">A <dfn title="specializationOf">specialization relation</dfn><span class="withPn">, written <span class="pnExpression">specializationOf(sub, super)</span> in PROV-N,</span> addresses case (2). It has the following constituents:
+<div class="attributes" id="attributes-specialization">A <dfn title="specializationOf">specialization</dfn> relation<span class="withPn">, written <span class="pnExpression">specializationOf(sub, super)</span> in PROV-N,</span> has the following constituents:
<ul>
-<li><span class='attribute' id="specialization.specializedEntity">specializedEntity</span>: an identifier of the specialized entity;</li>
-<li><span class='attribute' id="specialization.generalEntity">generalEntity</span>: an identifier of the entity that is being specialized.</li>
+<li><span class='attribute' id="specialization.specializedEntity">specializedEntity</span>: an identifier (<span class="name">sub</span>) of the specialized entity;</li>
+<li><span class='attribute' id="specialization.generalEntity">generalEntity</span>: an identifier (<span class="name">super</span>) of the entity that is being specialized.</li>
</ul>
</div>
<div class="anexample" id="anexample-specialization">
-<p>The following expressions describe two persons, the second of which is holder of a Twitter account. The second entity is a specialization of the first. </p>
+<p>
+The BBC news home page on 2012-03-23 <span class="name">ex:bbcNews2012-03-23</span>
+is a specialization of the BBC news page in general
+ <a href="http://www.bbc.co.uk/news/">bbc:news/</a>. This can be expressed as follows.
<pre class="codeexample">
-entity(ex:Bob, [ prov:type="person", ex:name="Bob" ])
-entity(twitter:XYZ, [ prov:type="person with Twitter account" ])
-specializationOf(twitter:XYZ, ex:Bob)
+specializationOf(ex:bbcNews2012-03-23, bbc:news/)
</pre>
+Given that the BBC news does not define a URI for today's news page, we are creating a qualified name in the namespace <span class="name">ex</span>.
</div>
+
+
<!--
<p>To promote take up of these relations, it is not specified whether they are transitive or symmetric. We anticipate that applications will specialize these relations according to their needs. </p>
-->
-<div class='issue'>A discussion on alternative definition of these relations has not yet reached a satisfactory conclusion. This is <a
-href="http://www.w3.org/2011/prov/track/issues/29">ISSUE-29</a>. Also <a href="http://www.w3.org/2011/prov/track/issues/96">ISSUE-96</a>.</div>
</section>
+
+<section id="term-alternate">
+
+<h4>Alternate</h4>
+
+
+<span class="glossary" id="glossary-alternate">
+An entity is <dfn id="concept-alternate">alternate</dfn> of another if they are both a specialization of some common entity.
+The common entity does not need to be identified.
+</span>
+
+
+
+
+<p><div class="attributes" id="attributes-alternate">An <dfn title="alternateOf">alternate</dfn> relation<span class="withPn">, written <span class="pnExpression">alternateOf(e1, e2)</span> in PROV-N,</span> has the following constituents:
+<ul>
+<li><span class='attribute' id="alternate.alternate1">alternate1</span>: an identifier (<span class="name">e1</span>) of the first of the two entities;</li>
+<li><span class='attribute' id="alternate.alternate2">alternate2</span>: an identifier (<span class="name">e2</span>) of the second of the two entities.</li>
+</ul>
+</div>
+
+<div class="anexample" id="anexample-alternate">
+<p>
+A given news item on the BBC News site
+ <a href="http://www.bbc.co.uk/news/science-environment-17526723">bbc:news/science-environment-17526723</a> for desktop
+is an alternate of a
+ <a href="http://www.bbc.co.uk/news/mobile/science-environment-17526723">bbc:news/mobile/science-environment-17526723</a> for mobile devices.</p>
+<pre class="codeexample">
+entity(bbc:news/science-environment-17526723, [ prov:type="a news item"])
+entity(bbc:news/mobile/science-environment-17526723, [ prov:type="a news item"])
+alternateOf(bbc:news/science-environment-17526723, bbc:news/mobile/science-environment-17526723)
+</pre>
+<p>They are both specialization of an (unspecified) entity. </p>
+</div>
+
+
+<div class="anexample" id="anexample-alternate2">
+<p>
+Considering again the two versions of the technical report <span class="name"><a href="http://www.w3.org/TR/2011/WD-prov-dm-20111215">tr:WD-prov-dm-20111215</a></span> (second working draft) and <span class="name"><span class="name"><a href="http://www.w3.org/TR/2011/WD-prov-dm-20111018">tr:WD-prov-dm-20111018</a></span></span> (first working draft). They are alternate of each other.
+<pre class="codeexample">
+entity(tr:WD-prov-dm-20111018)
+entity(tr:WD-prov-dm-20111215)
+alternateOf(tr:WD-prov-dm-20111018,tr:WD-prov-dm-20111215)
+</pre>
+<p>They are both specialization of the page <a href="http://www.w3.org/TR/prov-dm/">http://www.w3.org/TR/prov-dm/</a>.</p>
+</div>
+
+</section>
+
+<div class='issue'>A discussion on alternative definition of these relations has not yet reached a satisfactory conclusion. This is <a
+href="http://www.w3.org/2011/prov/track/issues/29">ISSUE-29</a>. Also <a href="http://www.w3.org/2011/prov/track/issues/96">ISSUE-96</a>.</div>
+
</section>
@@ -2214,8 +2227,8 @@
<p></p><div class="attributes" id="attributes-annotation">An <dfn title="hasAnnotation">annotation relation</dfn><span class="withPn">, written <span class="pnExpression">hasAnnotation(r,n)</span> in PROV-N,</span> has the following constituents:
<ul>
-<li><span class='attribute' id="annotation.id">something</span>: the identifier of something being annotated;</li>
-<li><span class='attribute' id="annotation.note">note</span>: an identifier of a note.</li>
+<li><span class='attribute' id="annotation.id">something</span>: the identifier (<span class="name">r</span>) of something being annotated;</li>
+<li><span class='attribute' id="annotation.note">note</span>: an identifier (<span class="name">n</span>) of a note.</li>
</ul>
</div>