--- a/model/ProvenanceModel.html Wed Sep 07 12:06:04 2011 +0100
+++ b/model/ProvenanceModel.html Wed Sep 07 12:44:39 2011 +0100
@@ -847,7 +847,7 @@
<span class="nonterminal">derivation</span> :=
<span class="nonterminal">pe-linked-derivation</span>
| <span class="nonterminal">pe-independent-derivation</span>
-| <span class="nonterminal">transitive-derivation</span><br/>
+| <span class="nonterminal">transitiveDerivation</span><br/>
<span class="nonterminal">pe-linked-derivation</span>:=
<span class="name">wasDerivedFrom</span>
@@ -871,7 +871,7 @@
<span class="nonterminal">identifier</span>
<span class="name">)</span><br/>
-<span class="nonterminal">transitivederivation</span>:=
+<span class="nonterminal">transitiveDerivation</span>:=
<span class="name">dependedOn</span>
<span class="name">(</span>
<span class="nonterminal">identifier</span>
@@ -1005,12 +1005,12 @@
-<p>A process execution independent derivation states the existence of a derivation, by any means whether direct or not, and regardless of any process executions. </p>
+<p>A process execution independent derivation expression is a representation of a derivation, which occurred by any means whether direct or not, and regardless of any activity in the world.</p>
-<p>A process execution independent derivation, written <span class="name">wasEventuallyDerivedFrom (e2, e1)</span>,
+<p>A process-execution independent derivation expression, written <span class="name">wasEventuallyDerivedFrom (e2, e1)</span> in the Provenance Abstract Syntax Notation,
<ul>
-<li> refers to an entity <span class="name">e2</span>, denoting the used characterized thing;
-<li> refers to an entity <span class="name">e1</span>, denoting the generated characterized thing;
+<li> contains an identifier <span class="name">e2</span>, denoting an entity, which represents the generated characterized thing;
+<li> contains an identifier <span class="name">e1</span>, denoting an entity, which represents the used characterized thing.
</ul>
@@ -1019,8 +1019,8 @@
which at the minimum implies temporal ordering, specified as follows:</p>
<div class='constraint' id='derivation-generation-generation-ordering'>
- <a name="PIL:0012">Given two entities <span class="name">e1</span> and <span class="name">e2</span>, if the assertion <span class="name">wasEventuallyDerivedFrom(e2,e1)</span>
- holds, then:
+ <a name="PIL:0012">Given two entities denoted by <span class="name">e1</span> and <span class="name">e2</span>, <span class='conditional'>if</span> the assertion <span class="name">wasEventuallyDerivedFrom(e2,e1)</span>
+ holds, <span class='conditional'>then</span> the
generation of the characterized thing denoted by <span class="name">e1</span> precedes the generation of
the characterized thing denoted by <span class="name">e2</span>.</a>
[<a href="../ontology/ProvenanceFormalModel.html#PIL:0012">PIL:0012</a>]
@@ -1047,19 +1047,28 @@
<p>
If <span class="name">wasDerivedFrom(e2,e1)</span> holds because attribute <span class="name">a2.1</span> of <span class="name">e2</span> is determined by attribute <span class="name">a1.1</span> of <span class="name">e1</span>,
-and if <span class="name">wasDerivedFrom(e3,e2)</span> holds because attribute <span class="name">a3.1</span>of <span class="name">e3</span> is determined by attribute <span class="name">a2.2</span> of <span class="name">e1</span>, it is not necessarily the case that an attribute of <span class="name">e3</span> is determined by an attribute of <span class="name">e1</span>, so, an asserter may not be able to assert <span class="name">wasDerivedFrom(e3,e1)</span>. Hence, constraints on attributes invalidate transitivity in the general case.
+and if <span class="name">wasDerivedFrom(e3,e2)</span> holds because attribute <span class="name">a3.1</span>of <span class="name">e3</span> is determined by attribute <span class="name">a2.2</span> of <span class="name">e1</span>, it is not necessarily the case that an attribute of <span class="name">e3</span> is determined by an attribute of <span class="name">e1</span>; so, an asserter may not be able to assert <span class="name">wasDerivedFrom(e3,e1)</span>, since it would fail to satisfy constraint <a href="#derivation-attributes">derivation-attributes</a>. Hence, the constraint on attributes as expressed in <a href="#derivation-attributes">derivation-attributes</a> invalidates transitivity in the general case.
</p>
<p>However, there is sense that <span class="name">e3</span> still depends on <span class="name">e1</span>, since <span class="name">e3</span> could not be generated without <span class="name">e1</span> existing. Hence, we introduce a weaker notion of derivation, which is transitive.</p>
-<p>The relationship <dfn id="dfn-dependedOn">dependedOn</dfn> is defined as follows:
+An instance of a transitive derivation expression, written <span class="name">dependedOn(e2, e1)</span> in the Provenance Abstract Syntax Notation:
+<ul>
+<li> contains an identifier <span class="name">e2</span>, denoting an entity, which represents the characterized thing that is the result of the derivation;
+<li> contains an identifier <span class="name">e1</span>, denoting an entity, which represents the characterized thing that the derivation depends on.
+</ul>
+<p>The expression <span class="name">dependedOn</span> can only be inferred; in other word, it cannot be asserted. It is
+transitive by definition and relies onn the previously defined derivation assertions for its
+base case.</p>
+
+<div class='constraint' id='transitive-derivation'>
<ul>
-<li>If <span class="name">wasDerivedFrom(e2,e1)</span> or <span class="name">wasDerivedFrom(e2,e1,pe,r2,r1)</span> holds, then <span class="name">dependedOn(e2,e1)</span>.</li>
-<li>If <span class="name">wasEventuallyDerivedFrom(e2,e1)</span> holds, then <span class="name">dependedOn(e2,e1)</span>.</li>
-<li>If <span class="name">dependedOn(e3,e2)</span> and <span class="name">dependedOn(e2,e1)</span> hold, then <span class="name">dependedOn(e3,e1)</span>.</li>
+<li><span class='conditional'>If</span> <span class="name">wasDerivedFrom(e2,e1)</span> or <span class="name">wasDerivedFrom(e2,e1,pe,r2,r1)</span> holds, <span class='conditional'>then</span> <span class="name">dependedOn(e2,e1)</span> holds.</li>
+<li><span class='conditional'>If</span> <span class="name">wasEventuallyDerivedFrom(e2,e1)</span> holds, <span class='conditional'>then</span> <span class="name">dependedOn(e2,e1)</span> holds..</li>
+<li><span class='conditional'>If</span> <span class="name">dependedOn(e3,e2)</span> and <span class="name">dependedOn(e2,e1)</span> hold, <span class='conditional'>then</span> <span class="name">dependedOn(e3,e1)</span> holds.</li>
</ul>
+</div>
-<p>We note that <span class="name">dependedOn</span> cannot be asserted but can only be inferred.</p>
</section>