Semantics sec. comments Pat
--- 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