process execution introduction inference; default roles; placeholder for transitivity
authorLuc Moreau <l.moreau@ecs.soton.ac.uk>
Tue, 26 Jul 2011 23:07:33 +0100
changeset 56 da3b731c2feb
parent 55 d61fe24776b0
child 57 ea43c184740d
process execution introduction inference; default roles; placeholder for transitivity
model/ProvenanceModel.html
--- a/model/ProvenanceModel.html	Tue Jul 26 18:20:23 2011 +0100
+++ b/model/ProvenanceModel.html	Tue Jul 26 23:07:33 2011 +0100
@@ -173,7 +173,7 @@
 <tr><td>e3:</td><td> holds in interval [t+3,t+4[</td></tr>
 <tr><td>e4:</td><td> the information piped to sendmail at t+2 (that's a copy of e2's content)</td></tr>
 <tr><td>e5:</td><td> the information piped to sendmail at t+4 (that's a copy of e3's content)</td></tr>
-<tr><td>e6:</td><td> a different view of the C-entity described by e3. It strictly contains all of e3's attributes, and it has an extra one, "disclaimer", and is therefore an IVP-of e3. Note that   no other assertions (i.e., on generation) is available for this BOB.</td></tr>
+<tr><td>e6:</td><td> holds in interval [t+3,t+4[; a different view of the characterized entity represented by e3. </td></tr>
 </table>
 </p>
 
@@ -225,11 +225,12 @@
 <p>
 IVP of:   (this relation is described at <a href="#IVP-of">IVP-of</a>)
 <pre>
-IVPof(e1,e0)
-IVPof(e2,e0)
-IVPof(e3,e0)
-IVPof(e6,e3) 
+ivpOf(e1,e0)
+ivpOf(e2,e0)
+ivpOf(e3,e0)
+ivpOf(e6,e3) 
 </pre>
+Note that e6 strictly contains all of e3's attributes, and it has an extra one, "disclaimer", and is therefore an ivpOf e3. Note that no other assertions (i.e., on generation) is available for this BOB.
 </p>
 
 
@@ -514,8 +515,8 @@
 
 
 <p>From an assertion <b>isDerivedFrom(B,A)</b>, the values of some
-characteristics of B are at least partially determined by the values
-of some characteristics of A.</p>
+attributes of B are at least partially determined by the values
+of some attributes of A.</p>
 
 
 
@@ -523,6 +524,36 @@
 of characterized entity denoted by <b>A</b> precedes the generation of
 the characterized entity denoted by <b>B</b>.
 
+<section>
+<h4>Relationship between derivation and process execution</h4>
+
+
+<p>A derivation, which by definition expresses that some characterized entity is transformed from, created from, or affected by another characterized entity, entails a process execution that transforms, creates or affects this characterized entity.</p>
+
+<p>This is formalized by a novel inference, referred to as <em>process execution introduction</em>:
+if <b>isDerivedFrom(e1,e0)</b> holds, then there exists a process execution <b>pe</b>, and roles <b>r0</b>,<b>r1</b>,
+such that:
+  <b>isGeneratedBy(e1,pe,r1)</b> and <b>use(pe,e0,r0)</b>.</p>
+
+<p>
+The converse inference does not hold. Indeed, when a generation <b>isGeneratedBy(e1,pe,r1)</b> precedes <b>use(pe,e0,r0)</b>,  for some <b>e0</b>, <b>e1</b>, <b>r0</b>, <b>r1</b>, and <b>pe</b>, one cannot infer derivation <b>isDerivedFrom(e1,e0)</b> since the values of attributes of <b>e1</b> cannot possibly be determined by the values of attributes of <b>e0</b>, given the creation of <b>e1</b> precedes the use of <b>e0</b>.
+</p>
+
+
+</section>
+<section>
+<h4>Transitivity</h4>
+
+<div class="note">
+To distinguish  
+<ul>
+<li>The assertion <b>isDerivedFrom(e1,e0)</b> corresponding to a single process execution, as per process execution introduction inference;
+<li>The relation <b>isDerivedFrom+(e1,e0)</b> obtained by transitive closure of <b>isDerivedFrom</b>;
+<li>The assertion <b>isDerivedFromInMultipleSteps(e1,e0)</b>, which may correspond to one or more process executions.
+</div>
+</section>
+
+
 <div class='issue'>Is derivation transitive? If so, it should not be introduced as an assertion.  This is <a href="http://www.w3.org/2011/prov/track/issues/45">ISSUE-45</a>.</div>
 
 <div class='issue'>Should derivation have a time? Which time? This is   <a href="http://www.w3.org/2011/prov/track/issues/43">ISSUE-43</a>.</div>
@@ -589,9 +620,9 @@
 
 <h3>IVP of</h3>
 
-<div class="note">We propose to replace the relation  "IPV of" with "complement of". The new term is used in the text below to "test" and see how it fits...</div>
+<div class="note">We propose to replace the relation  "IVP of" with "complement of". The new term is used in the text below to "test" and see how it fits...</div>
 
-<p><dfn id="VPN-of">VPN of</dfn> is a relationship between two characterized entities asserted to have compatible characterization over some continuous time interval.<br/>
+<p><dfn id="IVP-of">IVP of</dfn> is a relationship between two characterized entities 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 entity, which are reflected in assertions possibly made by different asserters. In the example that follows, suppose entity "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/>
@@ -611,7 +642,7 @@
 -->
 </p>
 
-<p>An IVP assertion is denoted <b>IVPof(B,A)</b>, where A and B are two BOBs.
+<p>An IVP assertion is denoted <b>ivpOf(B,A)</b>, where A and B are two BOBs.
 
 <p>
 <pre class="example">
@@ -648,7 +679,7 @@
 
 <div class='issue'>Do we need a sameAsEntity relation. This is <a href="http://www.w3.org/2011/prov/track/issues/35">ISSUE-35</a></div>
 
-<div class='issue'>Is IVPof transitive? This is <a href="http://www.w3.org/2011/prov/track/issues/45">ISSUE-45</a></div>
+<div class='issue'>Is ivpOf transitive? This is <a href="http://www.w3.org/2011/prov/track/issues/45">ISSUE-45</a></div>
 </section>
 
 <section id="concept-Time">
@@ -686,9 +717,19 @@
 <p>A <dfn id="dfn-Role">role</dfn> is a label that names the function assumed by a BOB or
 an agent with respect to a specific process execution.</p> 
 
-<p>Use, Generation, and Control assertions MUST contain a role.</p>
+<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 roles are unknown by the
+asserter, syntactic notations MAY allow for roles not to be
+expressed. In such a case, a default, uniquely named role from the set
+'unspecified role' will be assumed; the unspecified roles are
+<b>unspecified0</b>, <b>unspecified1</b>, <b>unspecified2</b>, ....
 
-
+<pre class="example">
+   use(pe,e)   expands to    use(pe,e,unspecified)
+</pre>
+where unspecified 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>