Semantics sec. comments Pat
authorGuus Schreiber <guus.schreiber@vu.nl>
Mon, 02 Dec 2013 14:44:01 +0100
changeset 1436 4fdb81502f43
parent 1435 0166327b6377
child 1437 2cac0bb3b3cc
Semantics sec. comments Pat
rdf-primer/index.html
--- a/rdf-primer/index.html	Sat Nov 30 02:06:03 2013 +0100
+++ b/rdf-primer/index.html	Mon Dec 02 14:44:01 2013 +0100
@@ -936,9 +936,10 @@
 
     <p class="note">Optional section</p>
    
-    <p>RDF is grounded in a formal model-theoretic semantics which is specified in the RDF
-    Semantics document [[RDF11-MT]]. This document takes a logical stance on RDF
-    graphs; it specifies truth-preserving conditions of RDF graphs as
+    <p>RDF is grounded in a formal model-theoretic semantics which is
+    specified in the RDF 
+    Semantics document [[RDF11-MT]]. This document
+    specifies truth-preserving conditions of RDF graphs as
     well as valid derivations from RDF graphs. Such logical
     consequences are called <a
     href="http://www.w3.org/TR/2013/CR-rdf11-mt-20131105/#semantic-extensions-and-entailment-regimes">entailments</a>. For
@@ -977,47 +978,48 @@
    and language-tagged literals.</p>
 
    <p>Unlike many other data
-   modeling languages, RDF Schema allows the same entity to be used
-   both as a class and as a property. Therefore, RDF semantics views the following graph
-   as valid:</p>
+   modeling languages, RDF Schema allows considerble modelling
+   freedomm. For example, the same entity may be used
+   as both a class and a property. Also, there is no strict separation
+   between the world of "classes" and of "instances". Therefore, RDF
+   semantics views the following graph as valid:</p>
    <pre>
-   <code>ex:Marriage rdf:type rdf:Property .</code>
-   <code>ex:Marriage rdf:type rdfs:Class . </code>
+   <code>ex:Jumbo rdf:type ex:Elephant .</code>
+   <code>ex:Elephant rdf:type ex:Species .</code>
+   <code>ex:Species rdf:type rdfs:Class .</code>
    </pre>
 
-<p class="issue">Consider replacing the example above with an example
-where a resource is both a class and an instance.</p>
-
    <p>The examples in this section are just meant to give the reader
 some feeling about what the RDF Semantics brings you. Please consult
 [[RDF11-MT]] for a complete description.</p>
 
-
-  <p class="issue">Should we discuss in this section the
-(non)semantics of multiple graphs? Should we discuss what happens if
-you import/merge multiple graphs? </p>
-
-<p class="issue">Mention that semantics views graphs as snapshots?! </p>
-</section>
+   </section>
 
    <section id="section-data">
 
     <h2>RDF Data</h2>
 
-    <p>A large amount of RDF data is available as part of the Linked Data [[LINKED-DATA]] cloud.
-    Datasets are being published and interlinked on the Web using RDF, and many of them offer
-    a querying facility through SPARQL [[!SPARQL11-OVERVIEW]]. Examples of such datasets used
-    in the examples above include:</p>
+    <p>A large amount of RDF data is available as part of the Linked
+    Data [[LINKED-DATA]] cloud. Datasets are being published and
+    interlinked on the Web using RDF, and many of them offer a
+    querying facility through SPARQL [[!SPARQL11-OVERVIEW]]. Examples
+    of such datasets used in the examples above include:</p>
 
     <ul>
-      <li><a href="http://www.wikidata.org/">Wikidata</a>, a free, collaborative and multilingual database and ran by the
+      <li><a href="http://www.wikidata.org/">Wikidata</a>, a free,
+      collaborative and multilingual database and ran by the 
       <a href="http://www.wikimedia.org/">Wikimedia Foundation</a></li>
+      
       <li><a href="http://dbpedia.org/">DBpedia</a>, publishing data extracted
       from <a href="http://en.wikipedia.org/wiki/Help:Infobox">Wikipedia infoboxes</a>.
-      <li><a href="http://www.europeana.eu/">Europeana</a>, publishing data about cultural objects from
-      a large number of European institutions</li>
-      <li><a href="http://viaf.org/">VIAF</a>, publishing data about people, works and geographic places
-      from a number of national libraries and other agencies.</li>
+
+      <li><a href="http://www.europeana.eu/">Europeana</a>, publishing
+      data about cultural objects from a large number of European
+      institutions</li>
+      
+      <li><a href="http://viaf.org/">VIAF</a>, publishing data about
+      people, works and geographic places from a number of national
+      libraries and other agencies.</li> 
     </ul>
 
     <p>A list of datasets available within the Linked Data cloud is maintained at