--- a/model/working-copy/towards-wd4.html Tue Feb 07 10:37:59 2012 +0000
+++ b/model/working-copy/towards-wd4.html Tue Feb 07 12:53:27 2012 +0000
@@ -432,19 +432,6 @@
<p>Further considerations:</p>
<ul>
-
-<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>
-
-
<li>Activities are not entities, as explained below.</li>
</ul>
@@ -884,43 +871,30 @@
</section>
<section id="Derivation-Relation">
-<h4>Derivation Record</h4>
-
-<p>In PROV-DM, a <dfn id="dfn-Derivation">derivation record</dfn> is a representation that some entity is transformed from, created from, or affected by another entity in the world. </p>
-
-
-<p>Examples of derivation include the transformation of a canvas into a painting, the transportation of a person from London to New York, the transformation of a relational table into a
-linked data set, and the melting of ice into water.</p>
+<h4>Derivation</h4>
<p>According to <a href="#conceptualization">Section Conceptualization</a>, for an entity to be transformed from, created from, or affected by another in some way, there must be some
underpinning activities performing the necessary actions resulting in such a derivation.
However, asserters may not assert or have knowledge of these activities and associated details: they may not assert or know their number, they may not assert or know their identity, they may
not assert or know the attributes characterizing how the relevant entities are used or generated. To accommodate the varying circumstances of the various asserters, PROV-DM allows more or
-less precise records of derivation to be asserted. Hence, PROV-DM uses the terms <em>precise</em> and <em>imprecise</em> to characterize the different kinds of derivation record. We note
+less precise derivations to be asserted. Hence, PROV-DM uses the terms <em>precise</em> and <em>imprecise</em> to characterize the different kinds of derivations. We note
that the derivation itself is exact (i.e., deterministic, non-probabilistic), but it is its description, expressed in a derivation record, that may be imprecise. </p>
<p>The lack of precision may come from two sources:</p>
<ul>
<li> the number of activities that underpin a derivation is not asserted or known, or</li>
-<li> any of the other details that are involved in the derivation is not asserted or known; these include activity identities, generation and usage records, and their attributes.</li>
+<li> any of the other details that are involved in the derivation is not asserted or known; these include activity identities, generation and usage, and their attributes.</li>
</ul>
-<!--
-Furthermore, assuming that an asserter has full knowledge of an activity underpinning a derivation, the same activity can generally be modelled in terms of sub-activities, composed in a such
-a way as to deliver the same behavior. Hence, since activities can be modelled at arbitrary levels of granularity, there is a distinguished case in which a derivation between two entities
-<span class="name">e2</span> and <span class="name">e1</span> corresponds <em>exactly</em> to <em>one</em> activity that used <span class="name">e1</span> and generated <span
-class="name">e2</span>. This is to be contrasted to the case where one derivation corresponds to n activities, where n can be any number greater than 1.
-Hence, PROV-DM uses the terms <em>one-activity</em> and <em>n-activities</em> to distinguish these two cases.</p>
--->
<p>Hence, we can consider two axis. An activity number axis that has values <em>single</em>, <em>multiple</em>, and <em>unknown</em>, respectively representing the case where one activity
is known to have occurred, more than one activities are known to have occurred, or an unknown number of activities have occurred. Likewise, we can consider another axis to cover other
-details (identities, generation and usage records, attributes), with values <em>asserted</em> and <em>not asserted</em>. We can then form a matrix of possible derivations. Out of the six
+details (identities, generation, usage, and attributes), with values <em>asserted</em> and <em>not asserted</em>. We can then form a matrix of possible derivations. Out of the six
possibilities,
-PROV-DM offers three forms of derivation derivation records to cater for five othem, while the remaining one is not meaningful. The following table summarises names for the three kinds of
+PROV-DM offers three forms of derivations to cater for five of them, while the remaining one is not meaningful. The following table summarises names for the three kinds of
derivation, which we then explain.</p>
<div style="text-align: center;">
@@ -928,16 +902,16 @@
<caption>PROV-DM Derivation Type Summary</caption>
<tr><td colspan=2 rowspan=2></td><td colspan=2><em>other details</em> axis</td></tr>
<tr><td>asserted</td><td>not asserted</td></tr>
-<tr><td rowspan=3><em>activity number</em><br>axis</td><td>single</td><td><a>precise-1 derivation record</a></td><td><a>imprecise-1 derivation record</a></td></tr>
-<tr><td>multiple</td><td><a>imprecise-n derivation record</a></td><td rowspan=2><a>imprecise-n derivation record</a></td></tr>
+<tr><td rowspan=3><em>activity number</em><br>axis</td><td>single</td><td><a>precise-1 derivation</a></td><td><a>imprecise-1 derivation</a></td></tr>
+<tr><td>multiple</td><td><a>imprecise-n derivation</a></td><td rowspan=2><a>imprecise-n derivation</a></td></tr>
<tr><td>unknown</td><td>—</td></tr>
</table>
</div>
<ul>
-<li> The asserter asserts that derivation is due to exactly one activity, and all the details are asserted. We call this a precise-1 derivation record.</li>
-<li> The asserter asserts that derivation is due to exactly one activity, but other details, whether known or unknown, are not asserted. We call this an imprecise-1 derivation record.</li>
-<li> The following cases are captured by an imprecise-n derivation record.
+<li> The asserter asserts that derivation is due to exactly one activity, and all the details are asserted. We call this a precise-1 derivation.</li>
+<li> The asserter asserts that derivation is due to exactly one activity, but other details, whether known or unknown, are not asserted. We call this an imprecise-1 derivation.</li>
+<li> The following cases are captured by an imprecise-n derivation.
<ul>
<li> The asserter knows that multiple activities are involved or ignores the number of activities involved in the derivation, and other details are not asserted. </li>
<li> The asserter knows that multiple activities are involved in the derivation, and all their details are asserted. In this case, these activities are connected by means of generated and
@@ -955,87 +929,49 @@
When <span class="name">prov:steps="single"</span>, derivation is due to one activity; when <span class="name">prov:steps="any"</span>, the number of activities is multiple or not known.</p>
-<p>The three kinds of derivation records are successively introduced. Making use of the attribute <span class="name">steps</span>, we can distinguish the various derivation types.</p>
+<p>The three kinds of derivations are successively introduced. Making use of the attribute <span class="name">steps</span>, we can distinguish the various derivation types.</p>
-<p>A <dfn>precise-1 derivation record</dfn>, written <span class="name">wasDerivedFrom(id, e2, e1, a, g2, u1, attrs)</span> in PROV-ASN, contains:</p>
+<p>A <dfn>precise-1 derivation</dfn><span class="withAsn">, written <span class="name">wasDerivedFrom(id, e2, e1, a, g2, u1, attrs)</span> in PROV-ASN,</span> contains:</p>
<ul>
-<li><em>id</em>: an OPTIONAL identifier <span class="name">id</span> identifying the derivation record;</li>
-<li><em>generatedEntity</em>: the identifier <span class="name">e2</span> of an entity record, which is a representation of the generated entity;</li>
-<li><em>usedEntity</em>: the identifier <span class="name">e1</span> of an entity record, which is a representation of the used entity;</li>
-<li><em>activity</em>: an identifier <span class="name">a</span> of an activity record, which is a representation of the activity using and generating the above entities;</li>
-<li><em>generation</em>: an identifier <span class="name">g2</span> of the generation record pertaining to <span class="name">e2</span> and <span class="name">a</span>;</li>
-<li><em>usage</em>: an identifier <span class="name">u1</span> of the usage record pertaining to <span class="name">e1</span> and <span class="name">a</span>.</li>
-<li><em>attributes</em>: an OPTIONAL set of attribute-value pairs <span class="name">attrs</span> that describe the modalities of this derivation, optionally including the attribute-value
+<li><em>id</em>: an OPTIONAL identifier identifying the derivation;</li>
+<li><em>generatedEntity</em>: the identifier of the generation entity;</li>
+<li><em>usedEntity</em>: the identifier of the used entity;</li>
+<li><em>activity</em>: the identifier of the activity using and generating the above entities;</li>
+<li><em>generation</em>: the identifier the generation for the generated entity and activity;</li>
+<li><em>usage</em>: the identifier of the usage for the used entity and activity;</li>
+<li><em>attributes</em>: an OPTIONAL set of attribute-value pairs that describe the modalities of this derivation, optionally including the attribute-value
pair <span class="name">prov:steps="single"</span>.</li>
</ul>
-<p>It is OPTIONAL to include the attribute <span class="name">prov:steps</span> in a precise-1 derivation since the record already refers to the one and only one activity underpinning the
+<p>It is OPTIONAL to include the attribute <span class="name">prov:steps</span> in a precise-1 derivation since it already refers to the one and only one activity underpinning the
derivation.</p>
-<p>An <dfn>imprecise-1 derivation record</dfn>, written <span class="name">wasDerivedFrom(id, e2,e1, t, attrs)</span> in PROV-ASN, contains:</p>
+<p>An <dfn>imprecise-1 derivation</dfn><span class="withAsn">, written <span class="name">wasDerivedFrom(id, e2,e1, t, attrs)</span> in PROV-ASN,</span> contains:</p>
<ul>
-<li><em>id</em>: an OPTIONAL identifier <span class="name">id</span> identifying the derivation record;</li>
-<li><em>generatedEntity</em>: the identifier <span class="name">e2</span> of an entity record, which is a representation of the generated entity;</li>
-<li><em>usedEntity</em>: the identifier <span class="name">e1</span> of an entity record, which is a representation of the used entity;</li>
-<li><em>time</em>: an OPTIONAL "generation time" <span class="name">t</span>, the time at which the entity denoted by <span class="name">e2</span> was created;</li>
-<li><em>attributes</em>: a set of attribute-value pairs <span class="name">attrs</span> that describe the modalities of this derivation; it MUST include the attribute-value pair <span class="name">prov:steps="single"</span>.</li>
+<li><em>id</em>: an OPTIONAL identifier identifying the derivation;</li>
+<li><em>generatedEntity</em>: the identifier of the generated entity;</li>
+<li><em>usedEntity</em>: the identifier of the used entity;</li>
+<li><em>time</em>: an OPTIONAL "generation time", the time at which the entity was created;</li>
+<li><em>attributes</em>: a set of attribute-value pairs that describe the modalities of this derivation; it MUST include the attribute-value pair <span class="name">prov:steps="single"</span>.</li>
</ul>
-<p>An imprecise-1 derivation MUST include the attribute <span class="name">prov:steps</span>, since it is the only means to distinguish this record from an imprecise-n derivation
-record.</p>
+<p>An imprecise-1 derivation MUST include the attribute <span class="name">prov:steps</span>, since it is the only means to distinguish this derivation from an imprecise-n derivation.</p>
-<p>An <dfn>imprecise-n derivation record</dfn>, written <span class="name">wasDerivedFrom(id, e2, e1, t, attrs)</span> in PROV-ASN, contains:</p>
+<p>An <dfn>imprecise-n derivation</dfn><span class="withAsn">, written <span class="name">wasDerivedFrom(id, e2, e1, t, attrs)</span> in PROV-ASN,</span> contains:</p>
<ul>
-<li><em>id</em>: an OPTIONAL identifier <span class="name">id</span> identifying the derivation record;</li>
-<li><em>generatedEntity</em>: the identifier <span class="name">e2</span> of an entity record, which is a representation of the generated entity;</li>
-<li><em>usedEntity</em>: the identifier <span class="name">e1</span> of an entity record, which is a representation of the used entity;</li>
-<li><em>time</em>: an OPTIONAL "generation time" <span class="name">t</span>, the time at which the entity denoted by <span class="name">e2</span> was created;</li>
-<li><em>attributes</em>: an OPTIONAL set of attribute-value pairs <span class="name">attrs</span> that describe the modalities of this derivation; it optionally includes the attribute-value pair <span class="name">prov:steps="any"</span>.</li>
+<li><em>id</em>: an OPTIONAL identifier identifying the derivation;</li>
+<li><em>generatedEntity</em>: the identifier of the generated entity;</li>
+<li><em>usedEntity</em>: the identifier of the used entity;</li>
+<li><em>time</em>: an OPTIONAL "generation time", the time at which the entity was created;</li>
+<li><em>attributes</em>: an OPTIONAL set of attribute-value pairs that describe the modalities of this derivation; it optionally includes the attribute-value pair <span class="name">prov:steps="any"</span>.</li>
</ul>
-<p>It is OPTIONAL to include the attribute <span class="name">prov:steps</span> in an imprecise-n derivation record. It defaults to <span class="name">prov:steps="any"</span>.</p>
+<p>It is OPTIONAL to include the attribute <span class="name">prov:steps</span> in an imprecise-n derivation. It defaults to <span class="name">prov:steps="any"</span>.</p>
<p>None of the three kinds of derivation is defined to be transitive. Domain-specific specializations of these derivations may be defined in such a way that the transitivity property
holds.</p>
-<div class="withAsn">
-<p>In PROV-ASN, a derivation record's text matches the <span class='nonterminal'>derivationRecord</span> production of the grammar defined in this specification document.</p>
-
-<div class='grammar'>
-<span class="nonterminal">derivationRecord</span> ::=
-<span class="name">wasDerivedFrom</span>
-<span class="name">(</span>
-<span class="optional"> <span class="nonterminal">identifier</span>,</span>
-<span class="nonterminal">eIdentifier</span>
-<span class="name">,</span>
-<span class="nonterminal">eIdentifier</span>
-<span class="name">,</span>
-<span class="nonterminal">aIdentifier</span>
-<span class="name">,</span>
-<span class="nonterminal">gIdentifier</span>
-<span class="name">,</span>
-<span class="nonterminal">uIdentifier</span>
-<span class="nonterminal">optional-attribute-values</span>
-<span class="name">)</span><br/>
-|
-<span class="name">wasDerivedFrom</span>
-<span class="name">(</span>
-<span class="optional"> <span class="nonterminal">identifier</span>,</span>
-<span class="nonterminal">eIdentifier</span>
-<span class="name">,</span>
-<span class="nonterminal">eIdentifier</span>
-<span class="optional"><span class="name">,</span>
-<span class="nonterminal">time</span></span>
-<span class="nonterminal">optional-attribute-values</span>
-<span class="name">)</span>
-</div>
-<p>
-The first clause of the alternative, where the activity, generation and usage record identifiers are present formalizes a derivation record is precise-1. The second clause of the alternative, with optional time formalizes imprecise records. The distinction between imprecise-1 and imprecise-n is made by the
-attribute <span class="name">prov:steps</span>.
-</p>
-</div>
-
<div class="anexample">
<p>The following assertions state the existence of derivations.</p>
<pre class="codeexample">
@@ -1050,19 +986,19 @@
wasDerivedFrom(e2,e1,2012-01-18T16:00:00, [prov:steps="any"])
</pre>
<p>
-The first two are precise-1 derivation records expressing that the activity represented by the activity <span class="name">a4</span>, by
-using the entity denoted by <span class="name">e3</span> according to usage record <span class="name">u2</span>
+The first two are precise-1 derivations expressing that the activity identified by <span class="name">a4</span>, by
+using the entity denoted by <span class="name">e3</span> according to usage <span class="name">u2</span>
derived the
-entity denoted by <span class="name">e5</span> and generated it according to generation record
- <span class="name">g2</span>.
+entity denoted by <span class="name">e5</span> and generated it according to generation
+ <span class="name">g2</span>. </p>
-
-The third record is an imprecise-1 derivation, which is similar for <span class="name">e3</span> and <span class="name">e2</span>, but it leaves the activity record and associated attributes implicit. The fourth and fifth records are imprecise-n derivation records between <span class="name">e2</span> and <span class="name">e1</span>, but no information is provided as to the number and identity of activities underpinning the derivation. The six derivation records extends the fifth with the derivation time of <span class="name">e2</span>.
+<p>
+The third record is an imprecise-1 derivation, which is similar for <span class="name">e3</span> and <span class="name">e2</span>, but it leaves the activity and associated attributes implicit. The fourth and fifth records are imprecise-n derivations between <span class="name">e2</span> and <span class="name">e1</span>, but no information is provided as to the number and identity of activities underpinning the derivation. The sixth derivation extends the fifth with the derivation time of <span class="name">e2</span>.
</p>
</div>
-<p>An precise-1 derivation record is richer than an imprecise-1 derivation record, itself, being more informative that an imprecise-n derivation record. Hence, the following implications
+<p>An precise-1 derivation is richer than an imprecise-1 derivation, itself, being more informative that an imprecise-n derivation. Hence, the following implications
hold.</p>
<div class='inference' id='derivation-implications'>
Given two entity records denoted by <span class="name">e1</span> and <span class="name">e2</span>, <span class='conditional'>if</span> the assertion <span class="name">wasDerivedFrom(e2,
@@ -1161,12 +1097,6 @@
<span class="name">wasDerivedFrom(e2,e1,attrs)</span> and <span class="name">wasGeneratedBy(e2,t)</span>.
</div>
-<p>
-<div class="structural-forward">
-See <a href="#derivation-use">derivation-use</a> for a structural constraint on derivation records.
-</div>
-</p>
-
<div class='pending'>Should derivation have a time? Which time? This is <a href="http://www.w3.org/2011/prov/track/issues/43">ISSUE-43</a>.<em>This is now addressed in this text. Optional time in derivation is generation time. See also <a href="http://www.w3.org/2011/prov/track/issues/205">ISSUE-205</a>.</em></div>