Merge pull request #62 from w3c/aligned_with_Concepts

Align Triple-term reification text with Concepts section (pending CR)

Author: domel

spec/index.html

@@ -824,20 +824,47 @@ <h3><code>rdf:nil</code></h3>
 
 <section id="ch_ttrei">
   <h2>Triple-term based reification</h2>
-  <p>A triple term is a construct defined in the RDF 1.2 Concepts and Abstract 
-    Syntax specification [[RDF12-CONCEPTS]], referring to an RDF triple that 
-    is used as a value, specifically, in the object position of another triple. 
-    Importantly, a triple term does not imply assertion; that is, the triple it 
-    denotes is not necessarily asserted in the RDF graph. This enables the 
-    representation of metadata or commentary about triples that may or may not 
-    be part of the asserted graph content, including potentially contradictory 
-    relationships. For a triple term to be considered an asserted triple, it 
-    must also appear explicitly in an RDF graph as a top-level triple. Otherwise, 
-    it remains unasserted and serves primarily as a reference or subject of metadata.</p>
-  <p>A triple term can be the object of a triple whose predicate is 
+  <p>
+    A triple term is a construct defined in [[RDF12-CONCEPTS]], referring to an RDF triple that is used 
+    as a value, specifically, in the object position of another triple. This use represents a reference to a proposition, 
+    and, importantly, a triple term does not by itself imply assertion; that is, the proposition it denotes 
+    is not necessarily a fact asserted by the RDF graph. This is only the case if that triple is also 
+    asserted in the RDF graph — that is, if it is a direct element of that set of triples.
+    Otherwise, it remains unasserted and serves primarily as a reference or as the subject of metadata. 
+    This enables the representation of metadata or commentary about triples that may or may not be part 
+    of the asserted graph content, including potentially contradictory relationships.
+  </p>
+
+  <p>
+    RDF terms that appear in a triple term have the same denotation as when they appear in an asserted 
+    triple in the graph. For this reason, triple terms are said to be <em>transparent</em>.
+  </p>
+
+  <p>
+    A triple term can be the object of a triple whose predicate is 
     <a href="#ch_reifies"><code>rdf:reifies</code></a>. In such cases, the resulting triple is referred 
-    to as a reifying triple, and its subject is termed a reifier. The reifier 
-    can be used to make further statements about the triple term.</p>
+    to as a <em><a data-cite="RDF12-CONCEPTS#dfn-reifying-triple">reifying triple</a></em>, and its subject is 
+    termed a <em><a data-cite="RDF12-CONCEPTS#dfn-reifier">reifier</a></em>. 
+    When the triple term of a reifying triple also appears in the same graph as an asserted triple, 
+    the subset of triples that share the same 
+    reifier as subject is called a <em><a data-cite="RDF12-CONCEPTS#dfn-triple-annotation">triple annotation</a></em>.
+  </p>
+
+  <p class="note">
+    When the underlying triple <code>S P O</code> is <strong>not</strong> asserted in the graph, a reifying triple (i.e., a triple whose predicate is <code>rdf:reifies</code> and whose object is the triple term <code>&lt;&lt;S P O&gt;&gt;</code>) together with further triples that use its <em>reifier</em> as subject constitute a description of the <em>reifier</em> resource, which denotes the proposition expressed by <code>&lt;&lt;S P O&gt;&gt;</code>. This is distinct from a <em>triple annotation</em> as defined in <a data-cite="RDF12-CONCEPTS#dfn-triple-annotation">RDF Concepts</a>, which requires that the underlying triple be asserted in the same graph.
+  </p>
+
+  <p>
+    Triple terms always denote abstract, logical propositions, while reifiers may denote a variety of 
+    things related to these propositions (such as a statement or belief that the proposition holds, or 
+    an event or circumstance that makes the proposition true). It is therefore expected that triple 
+    terms are commonly used as objects of reifying triples, and that reifiers (rather than the triple 
+    terms) are used in further descriptions. Because of the diversity of use cases that reifiers aim to 
+    serve, the meaning of the <code>rdf:reifies</code> property is deliberately generic. Multiple, 
+    distinct reifiers may exist for the same proposition (e.g., from different sources or contexts), and, 
+    conversely, one reifier may be used for several propositions.
+  </p>
+
   <section id="ch_proposition">
     <h3><code>rdfs:Proposition</code></h3>
     <p><code>rdfs:Proposition</code> is the class of reified triples.