1st nonrespec version
authorGuus Schreiber <guus.schreiber@vu.nl>
Tue, 03 Dec 2013 17:13:07 +0100
changeset 1463 e0b7c373f972
parent 1462 5ff575cdbc76
child 1464 376bf1ed0796
1st nonrespec version
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+</head>
+
+<body class="h-entry" role="document" id="respecDocument"><div class="head" role="contentinfo" id="respecHeader">
+  <p>
+    
+      <a href="http://www.w3.org/"><img width="72" height="48" alt="W3C" src="https://www.w3.org/Icons/w3c_home" /></a>
+    
+  </p>
+  <h1 property="dcterms:title" id="title" class="title p-name">RDF 1.1 Primer</h1>
+  
+  <h2 content="2013-12-03T16:08:37.000Z" datatype="xsd:dateTime" property="dcterms:issued" id="w3c-first-public-working-draft-03-december-2013"><abbr title="World Wide Web Consortium">W3C</abbr> First Public Working Draft <time datetime="2013-12-03" class="dt-published">03 December 2013</time></h2>
+  <dl>
+    
+      <dt>This version:</dt>
+      <dd><a href="http://www.w3.org/TR/2013/WD-rdf11-primer-20131203/" class="u-url">http://www.w3.org/TR/2013/WD-rdf11-primer-20131203/</a></dd>
+      <dt>Latest published version:</dt>
+      <dd><a href="http://www.w3.org/TR/rdf11-primer/">http://www.w3.org/TR/rdf11-primer/</a></dd>
+    
+    
+      <dt>Latest editor's draft:</dt>
+      <dd><a href="https://dvcs.w3.org/hg/rdf/raw-file/default/rdf-primer/index.html">https://dvcs.w3.org/hg/rdf/raw-file/default/rdf-primer/index.html</a></dd>
+    
+    
+    
+    
+    
+    
+      
+          <dt>Latest Recommendation:</dt>
+          <dd><a href="http://www.w3.org/TR/rdf-primer">http://www.w3.org/TR/rdf-primer</a></dd>
+      
+    
+    <dt>Editors:</dt>
+    <dd inlist="" rel="bibo:editor" class="p-author h-card vcard"><span typeof="foaf:Person"><a href="http://www.cs.vu.nl/~guus/" content="Guus Schreiber" property="foaf:name" rel="foaf:homepage" class="u-url url p-name fn">Guus Schreiber</a>, <a href="http://www.vu.nl/" class="p-org org h-org h-card" rel="foaf:workplaceHomepage">VU University Amsterdam</a></span>
+</dd>
+<dd inlist="" rel="bibo:editor" class="p-author h-card vcard"><span typeof="foaf:Person"><a href="http://raimond.me.uk/" content="Yves Raimond" property="foaf:name" rel="foaf:homepage" class="u-url url p-name fn">Yves Raimond</a>, <a href="http://www.bbc.co.uk" class="p-org org h-org h-card" rel="foaf:workplaceHomepage">BBC</a></span>
+</dd>
+
+    
+    
+      
+        
+          <dt>Previous Editors:</dt>
+          
+             
+                
+                  <dd>
+                    
+                      Frank Manola
+                    
+                  </dd>
+                
+             
+                
+                  <dd>
+                    
+                      Eric Miller
+                    
+                  </dd>
+                
+             
+                
+                  <dd>
+                    
+                      Brian McBride
+                    
+                  </dd>
+                
+             
+          
+        
+      
+    
+  </dl>
+  
+  
+  
+  
+    
+      <p class="copyright">
+        <a href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a> ©
+        2013
+        
+        <a href="http://www.w3.org/"><abbr title="World Wide Web Consortium">W3C</abbr></a><sup>®</sup>
+        (<a href="http://www.csail.mit.edu/"><abbr title="Massachusetts Institute of Technology">MIT</abbr></a>,
+        <a href="http://www.ercim.eu/"><abbr title="European Research Consortium for Informatics and Mathematics">ERCIM</abbr></a>,
+        <a href="http://www.keio.ac.jp/">Keio</a>, <a href="http://ev.buaa.edu.cn/">Beihang</a>), 
+        
+        All Rights Reserved.
+        
+        <abbr title="World Wide Web Consortium">W3C</abbr> <a href="http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liability</a>,
+        <a href="http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a> and
+        
+          <a href="http://www.w3.org/Consortium/Legal/copyright-documents">document use</a>
+        
+        rules apply.
+      </p>
+    
+  
+  <hr />
+</div>
+
+<div class="head" role="contentinfo" id="respecHeader">
+  <section id="abstract" class="introductory" property="dcterms:abstract" datatype="" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter"><h2 aria-level="1" role="heading" id="h2_abstract">Abstract</h2>
+
+    <p>The Resource Description Framework (RDF) is a language for
+    representing information about resources in the World Wide
+    Web. This primer is designed to provide the reader with the basic
+    knowledge required to effectively use RDF. It introduces the basic
+    concepts of RDF and shows concrete examples of the use of RDF. </p>
+</section><section class="introductory" id="sotd" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter"><h2 aria-level="1" role="heading" id="h2_sotd">Status of This Document</h2>
+  
+    
+      
+        <p>
+          <em>This section describes the status of this document at the time of its publication.
+          Other documents may supersede this document. A list of current <abbr title="World Wide Web Consortium">W3C</abbr> publications and the
+          latest revision of this technical report can be found in the <a href="http://www.w3.org/TR/"><abbr title="World Wide Web Consortium">W3C</abbr> technical reports index</a> at
+          http://www.w3.org/TR/.</em>
+        </p>
+        
+
+  <p>The RDF Working Group  expects this document to become a Working
+  Group Note. </p>
+  
+
+        <p>
+          This document was published by the <a href="http://www.w3.org/2011/rdf-wg/">RDF Working Group</a> as a First Public Working Draft.
+          
+          
+            If you wish to make comments regarding this document, please send them to 
+            <a href="mailto:[email protected]">[email protected]</a> 
+            (<a href="mailto:[email protected]?subject=subscribe">subscribe</a>,
+            <a href="http://lists.w3.org/Archives/Public/public-rdf-comments/">archives</a>).
+          
+          
+          
+          
+            All comments are welcome.
+          
+        </p>
+        
+        
+          <p>
+            Publication as a First Public Working Draft does not imply endorsement by the <abbr title="World Wide Web Consortium">W3C</abbr>
+            Membership. This is a draft document and may be updated, replaced or obsoleted by other
+            documents at any time. It is inappropriate to cite this document as other than work in
+            progress.
+          </p>
+        
+        
+        <p>
+          
+            This document was produced by a group operating under the 
+            <a href="http://www.w3.org/Consortium/Patent-Policy-20040205/" rel="w3p:patentRules" about="" id="sotd_patent">5 February 2004 <abbr title="World Wide Web Consortium">W3C</abbr> Patent
+            Policy</a>.
+          
+          
+            The group does not expect this document to become a <abbr title="World Wide Web Consortium">W3C</abbr> Recommendation.
+          
+          
+            
+              <abbr title="World Wide Web Consortium">W3C</abbr> maintains a <a rel="disclosure" href="http://www.w3.org/2004/01/pp-impl/46168/status">public list of any patent
+              disclosures</a> 
+            
+            made in connection with the deliverables of the group; that page also includes
+            instructions for disclosing a patent. An individual who has actual knowledge of a patent
+            which the individual believes contains
+            <a href="http://www.w3.org/Consortium/Patent-Policy-20040205/#def-essential">Essential
+            Claim(s)</a> must disclose the information in accordance with
+            <a href="http://www.w3.org/Consortium/Patent-Policy-20040205/#sec-Disclosure">section
+            6 of the <abbr title="World Wide Web Consortium">W3C</abbr> Patent Policy</a>.
+          
+          
+        </p>
+        
+      
+    
+  
+</section><section id="toc"><h2 class="introductory" aria-level="1" role="heading" id="h2_toc">Table of Contents</h2><ul class="toc" role="directory" id="respecContents"><li class="tocline"><a href="#section-Introduction" class="tocxref"><span class="secno">1. </span>Introduction</a></li><li class="tocline"><a href="#section-use-cases" class="tocxref"><span class="secno">2. </span>Why use RDF?</a></li><li class="tocline"><a href="#section-data-model" class="tocxref"><span class="secno">3. </span>RDF Data Model</a><ul class="toc"><li class="tocline"><a href="#subsection-triple" class="tocxref"><span class="secno">3.1 </span>Triples</a></li><li class="tocline"><a href="#subsection-IRI" class="tocxref"><span class="secno">3.2 </span>IRIs</a></li><li class="tocline"><a href="#subsection-literal" class="tocxref"><span class="secno">3.3 </span>Literals</a></li><li class="tocline"><a href="#subsection-blank-node" class="tocxref"><span class="secno">3.4 </span>Blank nodes</a></li><li class="tocline"><a href="#subsection-multiple-graphs" class="tocxref"><span class="secno">3.5 </span>Multiple graphs</a></li></ul></li><li class="tocline"><a href="#section-vocabulary" class="tocxref"><span class="secno">4. </span>RDF Vocabularies</a></li><li class="tocline"><a href="#section-graph-syntax" class="tocxref"><span class="secno">5. </span>Writing RDF graphs</a><ul class="toc"><li class="tocline"><a href="#subsection-turtle" class="tocxref"><span class="secno">5.1 </span>Turtle</a></li><li class="tocline"><a href="#subsection-trig" class="tocxref"><span class="secno">5.2 </span>TriG</a></li><li class="tocline"><a href="#subsection-other-syntaxes" class="tocxref"><span class="secno">5.3 </span>Other concrete syntaxes for RDF</a></li></ul></li><li class="tocline"><a href="#section-semantics" class="tocxref"><span class="secno">6. </span>Semantics of RDF Graphs</a></li><li class="tocline"><a href="#section-data" class="tocxref"><span class="secno">7. </span>RDF Data</a></li><li class="tocline"><a href="#section-conclusion" class="tocxref"><span class="secno">8. </span>More Information</a></li><li class="tocline"><a href="#section-Acknowledgments" class="tocxref"><span class="secno">A. </span>Acknowledgments</a></li><li class="tocline"><a href="#changes" class="tocxref"><span class="secno">B. </span>Changes</a></li><li class="tocline"><a href="#section-other-syntaxes" class="tocxref"><span class="secno">C. </span>Examples of RDF syntaxes</a><ul class="toc"><li class="tocline"><a href="#subsection-rdfa" class="tocxref"><span class="secno">C.1 </span>RDFa</a></li><li class="tocline"><a href="#subsection-jsonld" class="tocxref"><span class="secno">C.2 </span>JSON-LD</a></li><li class="tocline"><a href="#subsection-ntriples" class="tocxref"><span class="secno">C.3 </span>N-Triples</a></li><li class="tocline"><a href="#subsection-nquads" class="tocxref"><span class="secno">C.4 </span>N-Quads</a></li><li class="tocline"><a href="#subsection-rdf-xml" class="tocxref"><span class="secno">C.5 </span>RDF/XML</a></li></ul></li><li class="tocline"><a href="#references" class="tocxref"><span class="secno">D. </span>References</a><ul class="toc"><li class="tocline"><a href="#normative-references" class="tocxref"><span class="secno">D.1 </span>Normative references</a></li><li class="tocline"><a href="#informative-references" class="tocxref"><span class="secno">D.2 </span>Informative references</a></li></ul></li></ul></section>
+
+
+
+</div>
+
+<section id="section-Introduction" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    
+<!--OddPage-->
+<h2 aria-level="1" role="heading" id="h2_section-Introduction"><span class="secno">1. </span>Introduction</h2>
+
+    <div class="issue"><div class="issue-title" aria-level="2" role="heading" id="h_issue_1"><span>Issue 1</span></div><div class="">This document reflects current progress of the RDF Working
+      Group towards updating the
+      <a href="http://www.w3.org/TR/2004/REC-rdf-primer-20040210/">2004
+      version of the <em>RDF Primer</em></a>. The
+      editors expect to work on a number of issues, some of which are
+      listed in boxes like this throughout the document.</div></div>
+
+    <div class="note"><div class="note-title" aria-level="2" role="heading" id="h_note_1"><span>Note</span></div><p class="">This primer is an informative document. The
+    purpose is to give a light-weight overview of RDF 1.1.
+    Secs. 3-5 can be used as a minimalist introduction into the key
+    elements of RDF.</p></div> 
+      
+    <p>The Resource Description Framework (RDF) is a framework for
+    describing information about <strong>resources</strong> in the World Wide Web,
+    such as author and modification time of a
+    Web page or copyright and licensing information of a Web video.</p>
+
+    <p>RDF is intended for situations in which information on the Web needs to
+    be processed by applications, rather than being only displayed to
+    people. RDF provides a common framework for expressing this
+    information so it can be exchanged between applications without
+    loss of meaning. Since it is a common framework, application
+    designers can leverage the availability of common RDF parsers and
+    processing tools. The ability to exchange information between
+    different applications means that the information may be made
+    available to applications other than those for which it was
+    originally created. </p>
+
+    <p>In particular RDF can be used to publish and interlink data on the Web.
+    For example retrieving <code>http://www.example.org/bob</code>
+    could provide data about Bob, including the fact that he
+    knows Alice, as identified by her IRI.
+    Retrieving Alice's IRI could then provide more data about her, including links
+    to other datasets for her friends, interests, etc. A person or
+    an automated process can then follow such links and aggregate data about these
+    various things. Such uses of RDF are often
+    qualified as Linked Data [<cite><a class="bibref" href="#bib-LINKED-DATA">LINKED-DATA</a></cite>]. </p>
+
+    <div class="note"><div class="note-title" aria-level="2" role="heading" id="h_note_2"><span>Note</span></div><div class="">
+    An IRI is an &quot;International Resource Identifier&quot;. See Sec. <a href="#subsection-IRI">&quot;IRI&quot;</a> for details.
+    </div></div>
+    
+    <p>This document is not normative and does not give a complete
+    account of RDF 1.1. Normative
+    specifications of RDF can be found in the following documents: </p>
+    <ul>
+      <li>A document describing the basic concepts underlying RDF, as
+      well as abstract syntax (&quot;RDF Concepts and Abstract Syntax&quot;)
+      [<cite><a class="bibref" href="#bib-RDF11-CONCEPTS">RDF11-CONCEPTS</a></cite>]</li>
+      <li>A document describing the formal model-theoretic semantics
+      of RDF (&quot;RDF Semantics&quot;) [<cite><a class="bibref" href="#bib-RDF11-MT">RDF11-MT</a></cite>]</li>
+      <li>Specifications of concrete syntaxes for RDF:
+        <ul>
+	  <li>Turtle [<cite><a class="bibref" href="#bib-TURTLE">TURTLE</a></cite>] and TriG [<cite><a class="bibref" href="#bib-TRIG">TRIG</a></cite>]</li>
+	  <li>JSON-LD [<cite><a class="bibref" href="#bib-JSON-LD">JSON-LD</a></cite>] (JSON based)</li>
+	  <li>RDFa [<cite><a class="bibref" href="#bib-RDFA-PRIMER">RDFA-PRIMER</a></cite>] (for HTML embedding)</li>
+	  <li>N-Triples and N-Quads (line-based exchange formats)</li>
+	</ul></li> 
+      <li>A document describing RDF Schema [<cite><a class="bibref" href="#bib-RDF-SCHEMA">RDF-SCHEMA</a></cite>], which
+    provides a data-modeling vocabulary for RDF data. </li>
+    </ul>
+
+    
+<!--
+    <p>This primer provides a roadmap for people who want to study these
+    normative RDF documents (see Sec. <a href="#section-roadmap">"Roadmap"</a>). </p>
+    -->
+
+    
+</section>
+
+<section id="section-use-cases" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    
+<!--OddPage-->
+<h2 aria-level="1" role="heading" id="h2_section-use-cases"><span class="secno">2. </span>Why use RDF?</h2>
+
+    <p>The following illustrates various different uses of RDF, aimed
+    at different communities of practice.</p>
+
+    <ul>
+      <li>Adding machine-readable information to web pages using for example
+      the popular <a href="http://schema.org">schema.org</a>
+      vocabulary, enabling them to be displayed 
+      in an enhanced format on search engines or to be processed automatically
+      by third-party applications.</li>
+      <li>Enriching a dataset by linking it to third-party
+      datasets. For example a dataset about 
+      paintings could be enriched by linking them to the corresponding 
+      artists in <a href="http://www.wikidata.org">Wikidata</a>,  
+      therefore giving access to a wide range of information about
+      them and related resources.</li> 
+      <li>Interlinking API feeds, making sure that clients can easily
+      discover how to access more information.</li> 
+      <li>Using the datasets currently published as Linked Data
+      [<cite><a class="bibref" href="#bib-LINKED-DATA">LINKED-DATA</a></cite>], for example 
+      building aggregations of data around specific topics.</li>
+      <li>Building distributed social networks by interlinking RDF
+      descriptions of people 
+      across multiple web sites.</li>
+      <li>Providing a standard-compliant way for exchanging data
+      between RDF databases.</li> 
+      <li>Interlinking various datasets within an organisation,
+      enabling cross-dataset queries to 
+      be performed using SPARQL [<cite><a class="bibref" href="#bib-SPARQL11-OVERVIEW">SPARQL11-OVERVIEW</a></cite>].</li>
+    </ul>
+    
+</section>
+
+<section id="section-data-model" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+
+    
+<!--OddPage-->
+<h2 aria-level="1" role="heading" id="h2_section-data-model"><span class="secno">3. </span>RDF Data Model</h2>
+    
+    <section id="subsection-triple" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+
+    <h3 aria-level="2" role="heading" id="h3_subsection-triple"><span class="secno">3.1 </span>Triples</h3>
+    
+    <p>RDF allows us to make statements about resources.
+    The format of these statements is simple. It always
+    has the following form:</p><p>
+   </p><pre>      &lt;subject&gt;  &lt;predicate&gt; &lt;object&gt;
+    </pre>
+
+    
+<!--
+    <p>The <strong>subject</strong> represents the resource we like to
+    make a statement about. The <strong>predicate</strong> represents
+    a property of the subject. The
+    <strong>object</strong> represents a value of the property 
+    for this subject. Because RDF statements consist of three elements they are called
+    <strong>triples</strong>.</p>
+    -->
+
+    
+    <p>An RDF statement represents a relationship between two resources.
+    The <strong>subject</strong> and the <strong>object</strong>
+    represent the two resources being
+    related; the <strong>predicate</strong> represents the nature of their
+    relationship. The relationship is phrased in  a directional way
+    (from subject to object) and is called in RDF a
+    <strong>property</strong>.  Because RDF statements consist of
+    three elements they are called <strong>triples</strong>.
+    </p>
+
+    <div class="issue"><div class="issue-title" aria-level="3" role="heading" id="h_issue_2"><span>Issue 2</span></div><p class="">Should we define &quot;resource&quot;?</p></div>
+    
+    <p>Informally speaking, RDF allows us to make
+    statements of the form:</p> 
+
+    <div class="example"><div class="example-title"><span>Example 1</span></div><pre class="example">&lt;Bob&gt; &lt;is a&gt; &lt;person&gt;.
+&lt;Bob&gt; &lt;is a friend of&gt; &lt;Alice&gt;.
+&lt;Bob&gt; &lt;is born on&gt; &lt;the 4th of July 1990&gt;. 
+&lt;Bob&gt; &lt;is interested in&gt; &lt;the Mona Lisa&gt;.
+&lt;The Mona Lisa&gt; &lt;was created by&gt; &lt;Leonardo da Vinci&gt;.
+&lt;The video 'La Joconde à Washington'&gt; &lt;is about&gt; &lt;the Mona Lisa&gt;</pre></div>
+
+    <p>Resources typically occur in multiple 
+    triples, for example Bob and the Mona Lisa painting in the examples above. We
+    can therefore visualise triples as a connected
+    <strong>graph</strong>. Graphs consists 
+    of nodes and arcs. The subjects and
+    objects of the triples make up the nodes in the graph; the
+    predicates form the arcs. </p> 
+
+    <figure id="fig-informal-graph-of-the-sample-triples">
+      <img alt="Informal graphs of the sample triples" src="example-graph.jpg" />
+      <figcaption>Fig. <span class="figno">1</span> <span class="fig-title">Informal graph of the sample triples</span></figcaption>
+    </figure>
+ 
+    <p>The example above does not constitute actual RDF
+    syntax; it is just intended to provide an informal
+    view of the notion of an RDF graph. </p>
+
+    <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_3"><span>Note</span></div><p class="">The RDF Data Model is described in this section
+    in the form of an &quot;abstract syntax&quot;, i.e. a data model that is independent of a
+    particular encoding.  Different encodings may 
+    produce exactly the same graph from the perspective of the
+    abstract syntax. The semantics of RDF graphs [<cite><a class="bibref" href="#bib-RDF11-MT">RDF11-MT</a></cite>] are defined in
+    terms of this abstract syntax. RDF syntax is introduced
+    later in Sec. <a href="#section-graph-syntax">Writing RDF
+    graphs</a>.</p></div>
+
+    <p>In the next three subsections we discuss the three types of RDF data
+    that occur in triples: IRIs, literals and blank nodes. </p>
+    
+    </section>
+
+    <section id="subsection-IRI" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+
+    <h3 aria-level="2" role="heading" id="h3_subsection-IRI"><span class="secno">3.2 </span>IRIs</h3>
+
+    <p>The abbreviation IRI is short for &quot;International Resource
+    Identifier&quot;. An <a href="http://www.w3.org/TR/rdf11-concepts/#section-IRIs">IRI</a>
+    identifies a Web resource. The notion of IRI is a
+    generalization of URI (Uniform Resource Identifier), allowing
+    non-ASCII characters to be used in the IRI character string. IRIs are specified
+    in RFC 3987 [<cite><a class="bibref" href="#bib-RFC3987">RFC3987</a></cite>]. 
+
+    </p><p>IRIs can appear in <strong>all three positions</strong> of a triple. </p>
+
+    <p>IRIs can be used to identify both documents
+    (e.g. a Web page) and things (e.g. a person). 
+    For example, the IRI for the &quot;Mona Lisa&quot; painting in
+    <a href="http://www.wikidata.org/">Wikidata</a> is:</p>
+
+      <div class="example"><a href="http://www.wikidata.org/entity/Q12418">http://www.wikidata.org/entity/Q12418</a></div>
+
+      <p>The IRI for Leonardo da Vinci in <a href="http://dbpedia.org.org">DBpedia</a> is:</p>
+
+      <div class="example"><a href="http://dbpedia.org/resource/Leonardo_da_Vinci">http://dbpedia.org/resource/Leonardo_da_Vinci</a></div>
+
+      <p>The IRI for an <a href="http://www.ina.fr">INA</a> video about the Mona Lisa entitled 'La Joconde à Washington' in <a href="http://www.europeana.eu">Europeana</a> is:</p>
+
+      <div class="example"><a href="http://data.europeana.eu/item/04802/243FA8618938F4117025F17A8B813C5F9AA4D619">http://data.europeana.eu/item/04802/243FA8618938F4117025F17A8B813C5F9AA4D619</a></div>
+
+
+<!--
+    <figure>
+      <img src="example-graph-iris.jpg" 
+                alt="Informal graphs of the sample triples, with IRIs">
+      <figcaption>Informal graph of the sample triples, with IRIs</figcaption>
+    </figure>
+-->
+
+
+    <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_4"><span>Note</span></div><p class="">RDF is agnostic about what the IRI stands for. However,
+    IRIs may be given meaning by particular vocabularies or
+    conventions. For example, <a href="http://wiki.dbpedia.org/Datasets#h338-3">DBpedia</a>  uses IRIs of the form
+    <code>http://dbpedia.org/resource/Name</code> to denote the thing
+    described by the corresponding Wikipedia article.
+    RDF vocabularies are discussed in more detail in Sec.
+    <a href="#section-vocabulary">&quot;RDF vocabularies&quot;</a>. </p></div>
+    
+    </section>
+
+    <section id="subsection-literal" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+
+      <h3 aria-level="2" role="heading" id="h3_subsection-literal"><span class="secno">3.3 </span>Literals</h3>
+
+      <p><a href="http://www.w3.org/TR/rdf11-concepts/#section-Graph-Literal">Literals</a>
+      are basic values that are not IRIs. Examples of literals include
+      strings such as &quot;La Joconde&quot;, dates such as &quot;the 4th of July, 1990&quot;
+      and numbers such as &quot;3.14159&quot;. 
+      Literals are associated with a <i>datatype</i> enabling such
+      values to be parsed and interpreted correctly.  
+      String literals can optionally be associated with a <i>language
+      tag</i>. For example &quot;Léonard de Vinci&quot; could 
+      be associated with the &quot;fr&quot; language tag and &quot;李奥纳多·达·文西&quot;
+      with the &quot;zh&quot; language tag.</p> 
+      
+     <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_5"><span>Note</span></div><p class="">The RDF data model assigns the special datatype
+     <code>rdf:langString</code> to language-tagged literals.</p></div>
+      
+     <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_6"><span>Note</span></div><p class="">The 2004 version of RDF contained the notion of a
+     &quot;plain literal&quot; with no datatype. This feature has been removed, as the
+     distinction between &quot;plain&quot; literals and literals with datatype
+     <code>string</code> was confusing. RDF syntaxes such as Turtle allow
+     writing literals without an explicit datatype and treat this
+     as syntactic sugar for a <code>string</code> datatype.</p></div> 
+
+     <p>Literals may only appear in the <strong>object position</strong> of a triple.</p>
+
+     <p>The RDF Concepts document provides a (non-exhaustive)
+     <a href="http://www.w3.org/TR/rdf11-concepts/#section-Datatypes">list
+     of datatypes</a>.  This includes many datatypes defined by XML
+     Schema, such as string, boolean, integer, decimal and date. </p>
+      
+    </section>
+
+    <section id="subsection-blank-node" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+
+      <h3 aria-level="2" role="heading" id="h3_subsection-blank-node"><span class="secno">3.4 </span>Blank nodes</h3>
+
+      <p>IRIs and literals together provide the basic material for
+      writing down RDF statements. In addition, it is sometimes handy
+      to be able to talk about resources without bothering to use an
+      identifier.  For example, we might want to state that the Mona
+      Lisa painting has in its background an unidentified tree which
+      we know to be a cypress tree. Resources such as the unidentified
+      cypress tree are called <a href="http://www.w3.org/TR/rdf11-concepts/#section-blank-nodes">&quot;blank 
+      nodes&quot;</a> in RDF. A blank node indicates an un-named
+      thing. Blank nodes are like simple
+      variables in algebra; they represent some thing without saying
+      what their value is.
+      </p>
+
+      <p>Blank nodes can appear in the <strong>subject and object
+      position</strong> of a triple. They can be used 
+      to denote resources without explicitly naming them with an
+      IRI.</p>
+
+      
+<!--
+      <p class="note">Blank nodes can make RDF look complicated,
+      especially when one consults details about blank nodes in the RDF Concepts
+      [[RDF11-CONCEPTS]] and RDF Semantics [[RDF11-MT]] documents. It
+      should be noted that many RDF users in practice don't use blank nodes. </p> 
+      -->
+
+
+    </section>
+
+    <section id="subsection-multiple-graphs" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+
+      <h3 aria-level="2" role="heading" id="h3_subsection-multiple-graphs"><span class="secno">3.5 </span>Multiple graphs</h3>
+
+      <p>RDF provides a mechanism to group RDF statements in multiple
+      graphs and associate each graph with an IRI.</p><p> 
+
+      </p><p>For example, the
+      statements in the <a href="#subsection-triple">first example</a> could be grouped in two
+      graphs. A first graph could be provided by a social networking
+      site and identified by <code>http://example.org/bob</code>:</p> 
+
+      <pre>        &lt;Bob&gt; &lt;is a&gt; &lt;person&gt;.
+        &lt;Bob&gt; &lt;is a friend of&gt; &lt;Alice&gt;.
+        &lt;Bob&gt; &lt;is born on&gt; &lt;the 4th of July 1990&gt;.
+        &lt;Bob&gt; &lt;is interested in&gt; &lt;the Mona Lisa&gt;.
+      </pre>
+
+      <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_7"><span>Note</span></div><p class="">The IRI associated with the graph is
+      called the &quot;graph name&quot; in [<cite><a class="bibref" href="#bib-RDF11-CONCEPTS">RDF11-CONCEPTS</a></cite>]. However 
+      RDF 1.1 does not specify a particular semantics for the 
+      relation between the &quot;graph name&quot; and the graph [<cite><a class="bibref" href="#bib-RDF11-MT">RDF11-MT</a></cite>].</p></div>
+      
+      <p>A second graph could be provided by <a href="http://www.wikidata.org/">Wikidata</a> 
+      and identified by
+      <code>https://www.wikidata.org/wiki/Special:EntityData/Q12418</code>:</p> 
+
+      <pre>        &lt;Leonardo da Vinci&gt; &lt;is the creator of&gt; &lt;the Mona Lisa&gt;.
+        &lt;The video 'La Joconde à Washington'&gt; &lt;is about&gt; &lt;the Mona Lisa&gt;
+      </pre>
+
+      <p>We can then write down triples that include a graph name,
+      for example:</p>
+
+      <pre>        &lt;http://example.org/bob&gt; &lt;is published by&gt; &lt;http://example.org&gt;.
+        &lt;http://example.org/bob&gt; &lt;has license&gt; &lt;http://creativecommons.org/licenses/by/3.0/&gt;.
+      </pre>
+
+      <p>These two triples could be interpreted as license and
+      provenance information of the graph
+      <code>http://example.org/bob</code>.</p>
+
+      <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_8"><span>Note</span></div><p class="">RDF does not define the way in which the graph name
+      and the graph are related. It is therefore up to application developers to
+      decide how to interpret such triples.</p></div>
+
+      <div class="issue"><div class="issue-title" aria-level="3" role="heading" id="h_issue_3"><span>Issue 3</span></div><p class="">The text above is still being debated and may
+      be adapted/removed in future versions. 
+      </p></div>
+
+      <p>Multiple graphs in an RDF document constitute an <a href="http://www.w3.org/TR/rdf11-concepts/#section-dataset">RDF 
+      dataset</a>. An RDF dataset may have multiple named graphs and
+      one default graph (i.e. without a name). The default graph
+      could, for example, be used to record graph metadata, such as
+      the two last statements which constitute publisher and license
+      metadata about the first graph.</p>
+
+      <p>Sec. <a href="#trig-syntax">&quot;Trig syntax&quot;</a> provides an example
+    of concrete syntax for this example.</p>
+
+    <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_9"><span>Note</span></div><p class="">Multiple graphs are a recent extension of the RDF
+    data model. In practice, RDF tool builders and
+    data managers needed a mechanism to talk about subsets of
+    triples. Multiple graphs were first introduced in the RDF query
+    language SPARQL. The RDF data model was therefore extended with a notion of
+    multiple graphs that is closely aligned with SPARQL. </p></div> 
+
+    <figure id="fig-informal-graph-of-the-multiple-graphs-example">
+      <img alt="Informal graph of the multiple graphs example" src="example-multiple-graphs.jpg" />
+      <figcaption>Fig. <span class="figno">2</span> <span class="fig-title">Informal graph of the multiple graphs example</span></figcaption>
+    </figure>
+
+    <div class="issue"><div class="issue-title" aria-level="3" role="heading" id="h_issue_4"><span>Issue 4</span></div><p class="">TODO: update figure</p></div>
+
+    </section>
+
+</section>
+
+<section id="section-vocabulary" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+
+    
+<!--OddPage-->
+<h2 aria-level="1" role="heading" id="h2_section-vocabulary"><span class="secno">4. </span>RDF Vocabularies</h2>
+
+    <p>The RDF data model provides a way to make statements about
+    resources. As we mentioned, this data model does not make any
+    assumptions about what resource IRIs stand for. In practice, RDF
+    is typically used in combination with vocabularies or other
+    conventions that provide semantic information about these
+    resources. </p>
+
+    <p>To support the definition of vocabularies RDF provides
+    the RDF-Schema language
+    [<cite><a class="bibref" href="#bib-RDF-SCHEMA">RDF-SCHEMA</a></cite>]. This language allows one to define semantic
+    characteristics of
+    RDF data. For example, one can state that the IRI 
+    <code>ex:friendOf</code> can be used as a property and that the
+    subjects and objects of <code>ex:friendOf</code> triples must be
+    resources of class <code>ex:Person</code>. </p><p> 
+
+    </p><p>RDF Schema uses the notion of <strong>class</strong> to
+    specify categories that can be used to classify resources. The
+    relation between an instance and its class is modelled through the
+    <strong>type</strong> property. For both classes and properties one can create
+    subtype hierarchies. Type restrictions on the subjects
+    and objects of particular triples can be defined through
+    <strong>domain</strong> respectively <strong>range</strong> restrictions.</p>
+
+    <p>The main modeling
+    constructs provided by RDF Schema are summarized in the table below:</p>
+
+
+<table id="table-rdf-schema">
+  <tbody>
+    <tr>
+      <th>Construct</th>
+      <th>Syntactic form</th>
+      <th>Description</th>
+    </tr>
+    <tr>
+      <td><a href="http://www.w3.org/TR/rdf-schema/#ch_classes">Class</a> (a class)</td>
+      <td><strong>s</strong> <code>rdf:type rdfs:Class</code></td>
+      <td><strong>s</strong> (a resource) is an RDF class</td>
+    </tr>
+    <tr>
+      <td><a href="http://www.w3.org/TR/rdf-schema/#ch_property">Property</a> (a class)</td>
+      <td><strong>p</strong> <code>rdf:type rdf:Property</code></td>
+      <td><strong>p</strong> (a resource) is an RDF property</td>
+    </tr>
+    <tr>
+      <td><a href="http://www.w3.org/TR/rdf-schema/#ch_type">type</a> (a property)</td>
+      <td><strong>s</strong> <code>rdf:type</code> <strong>o</strong></td>
+      <td><strong>s</strong> (a resource) is an instance of <strong>o</strong> (a class)</td>
+    </tr>
+    <tr>
+      <td><a href="http://www.w3.org/TR/rdf-schema/#ch_subclassof">subClassOf</a> (a property)</td>
+      <td><strong>s</strong> <code>rdfs:subClassOf</code> <strong>o</strong></td>
+      <td><strong>s</strong> (a class) is a subclass of <strong>o</strong> (a class)</td>
+    </tr>
+    <tr>
+      <td><a href="http://www.w3.org/TR/rdf-schema/#ch_subpropertyof">subPropertyOf</a> (a property)</td>
+      <td><strong>s</strong> <code>rdfs:subPropertyOf</code> <strong>o</strong></td>
+      <td><strong>s</strong> (a property) is a sub-property of <strong>o</strong> (a property)</td>
+   </tr>
+    <tr>
+      <td><a href="http://www.w3.org/TR/rdf-schema/#ch_domain">domain</a> (a property)</td>
+      <td><strong>s</strong> <code>rdfs:domain</code> <strong>o</strong></td>
+      <td>domain of <strong>s</strong> (a property) is <strong>o</strong> (a class)</td>
+    </tr>
+    <tr>
+      <td><a href="http://www.w3.org/TR/rdf-schema/#ch_range">range</a> (a property)</td>
+      <td><strong>s</strong> <code>rdfs:range</code> <strong>o</strong></td>
+      <td>range of <strong>s</strong> (a property) is <strong>o</strong> (a class)</td>
+    </tr>
+  </tbody>
+</table>
+
+<div class="note"><div class="note-title" aria-level="2" role="heading" id="h_note_10"><span>Note</span></div><p class="">The syntactic form (second column) is in a prefix
+notation wich is discussed in more detail in Sec.
+<a href="#section-graph-syntax">&quot;Writing RDF Graphs&quot;</a>.
+The fact that the constructs have two different prefixes
+(<code>rdf:</code> and <code>rdfs:</code>) is a somewhat annoying
+historical artefact, which is preserved for backward
+compatibility.</p></div>
+
+<p>With the help of RDF Schema one can build a model of RDF data. A
+simple informal example:</p>
+
+  <div class="example"><div class="example-title"><span>Example 2</span></div><pre id="rdfs-example" class="example">&lt;Person&gt; &lt;<strong>type</strong>&gt; &lt;Class&gt;
+&lt;is a friend of&gt; &lt;<strong>type</strong>&gt; &lt;Property&gt;
+&lt;is a friend of&gt; &lt;<strong>domain</strong>&gt; &lt;Person&gt;
+&lt;is a friend of&gt; &lt;<strong>range</strong>&gt; &lt;Person&gt;
+&lt;is a good friend of&gt; &lt;<strong>subPropertyOf</strong>&gt; &lt;is a friend of&gt;</pre></div>
+
+<p>One of first RDF vocabularies used worldwide was the
+<a href="http://www.foaf-project.org/">&quot;Friend of a Friend&quot;</a> (FOAF)
+vocabulary for describing social networks. Other typical examples of RDF
+vocabularies are:</p>
+
+<dl>
+  <dt><a href="http://dublincore.org/documents/dcmi-terms/">Dublic Core</a></dt>
+  <dd>The Dublic Core Metadata Initiative maintains a metadata element
+  set for describing a wide range of resources. The vocabulary provides
+  properties such as &quot;creator&quot;, &quot;publisher&quot; and &quot;title&quot;.</dd>
+
+  <dt><a href="http://schema.org/">schema.org</a>
+  </dt><dd>Schema.org is a vocabulary developed by a group of major search
+  providers. The idea is that webmasters can use these terms to markup
+  webpages, so that search engines understand what the pages are
+  about.</dd>
+
+  <dt><a href="http://wordnet.princeton.edu/">WordNet</a></dt>
+  <dd>WordNet is a lexical database of English terms, grouped in sets
+  of synonyms, with a range of semantic interrelations. <abbr title="World Wide Web Consortium">W3C</abbr> make an
+  <a href="http://www.w3.org/2006/03/wn/wn20/">RDF version</a>
+  available of WordNet 2.0, which was one 
+  of the first elements of the <a href="http://linkeddata.org/">Linked
+  Data Cloud</a>. Similar databases exist for many other languages.</dd>
+
+  <dt><a href="http://www.w3.org/2004/02/skos/">SKOS</a></dt>
+  <dd>SKOS is a vocabulary for publishing classification schemes
+  such as terminologies and thesauri on the Web. SKOS is since 2009 a <abbr title="World Wide Web Consortium">W3C</abbr>
+  recommendation and is widely used in the library world. Library of
+  Congress published its Subject Headings as a <a href="http://id.loc.gov/authorities/subjects.html">SKOS
+  vocabulary</a>.</dd> 
+</dl>
+
+<p>For a formal specification of the semantics of the RDF Schema
+constructs the reader is referred to
+the RDF Semantics document [<cite><a class="bibref" href="#bib-RDF11-MT">RDF11-MT</a></cite>]. Users interested in more comprehensive
+semantic modeling of RDF data might consider using the OWL
+[<cite><a class="bibref" href="#bib-OWL2-OVERVIEW">OWL2-OVERVIEW</a></cite>]. OWL is a RDF vocabulary, so it can be
+used in combination with RDF Schema.</p>
+
+</section>
+
+<section id="section-graph-syntax" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+
+    
+<!--OddPage-->
+<h2 aria-level="1" role="heading" id="h2_section-graph-syntax"><span class="secno">5. </span>Writing RDF graphs</h2>
+
+    <p>Many different concrete syntaxes exist for writing down RDF
+    graphs. However, different encodings of the same graph lead
+    to exactly the same triples. </p>
+
+    <p>In the next two
+    subsections we show RDF syntax examples using the Turtle and Trig
+    language, because these two languages are best suited for human
+    consumption. The final subsection lists the other RDF syntaxes,
+    which include RDFa (for HTML embedding), JSON-LD (JSON-based syntax),
+    N-Triples/N-Quads (line-based exchange formats) and RDF/XML. In
+    Appendix <a href="#section-other-syntaxes">&quot;RDF syntax
+    examples&quot;</a> the reader can find for each RDF syntax
+    corresponding examples of the ones in this section. </p>
+
+    <section id="subsection-turtle" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+
+      <h3 aria-level="2" role="heading" id="h3_subsection-turtle"><span class="secno">5.1 </span>Turtle</h3>
+
+      <p>Turtle [<cite><a class="bibref" href="#bib-TURTLE">TURTLE</a></cite>] provides a syntax for RDF
+      graphs, which is relatively convenient for humans. Turtle
+      introduces a number of syntax shortcuts, such as
+      support for namespaces, lists and shorthands for datatyped 
+      literals. Turtle provides a trade-off between ease of
+      writing, ease of parsing and readability. Our 
+      <a href="#subsection-triple">first example</a> (in slightly
+      extended form) can be
+      represented in Turtle as follows:</p>
+
+      <div class="example"><div class="example-title"><span>Example 3</span></div><pre id="turtle-example" class="example">01    @base &lt;http://example.org/&gt; .
+02    @prefix foaf: &lt;http://xmlns.com/foaf/0.1/&gt; .
+03    @prefix xsd: &lt;http://www.w3.org/2001/XMLSchema#&gt; .
+04    @prefix schema: &lt;http://schema.org/&gt; .
+05    @prefix dcterms: &lt;http://purl.org/dc/terms/&gt; .
+06    @prefix wd: &lt;http://www.wikidata.org/entity/&gt; .
+07 
+08    &lt;bob#me&gt;
+09        a foaf:Person ;
+10        foaf:knows &lt;alice#me&gt; ;
+11        schema:birthDate &quot;1990-07-04&quot;^^xsd:date ;
+12        foaf:topic_interest wd:Q12418 .
+13
+14    &lt;http://dbpedia.org/resource/Leonardo_da_Vinci&gt;
+15        a foaf:Person ;
+16        foaf:name &quot;Leonardo da Vinci&quot; .
+17
+18    wd:Q12418
+19        dcterms:creator &lt;http://dbpedia.org/resource/Leonardo_da_Vinci&gt; .
+20
+21    &lt;http://data.europeana.eu/item/04802/243FA8618938F4117025F17A8B813C5F9AA4D61set&gt;
+22        dcterms:subject wd:Q12418 .</pre></div>
+
+<p>Lines 1-6 contain a number of directives which provide shorthands for
+writing down IRIs. In Turtle IRIs are enclosed in angle brackets
+(<code>&lt;&gt;</code>). Relative IRIs (such as <code>bob#me</code> on line 8) are 
+resolved agains a base IRI, specified here in line 1.
+Lines 2-6 define IRI prefixes (such as <code>foaf:</code>), which  can
+be use for prefixed names (such as <code>foaf:Person</code>) instead of full IRIs.
+The corresponding IRI is constructed by replacing the prefix with its
+corresponding IRI (in this example <code>foaf:Person</code> stands for
+<code>&lt;http://xmlns.com/foaf/0.1/Person&gt;</code>). A period is used to
+signal the end of a Turtle statement. </p>
+
+<div class="issue"><div class="issue-title" aria-level="3" role="heading" id="h_issue_5"><span>Issue 5</span></div><p class="">
+Use SPARQL-style prefix?
+</p></div>
+
+<p>Lines 8-12 show how Turtle provides a shorthand for a set of
+triples with the same subject. Lines 9-12 specify the predicate-object
+part of triples with <code>http://example.org/bob#me</code> as
+subject. The semicolons at the end of lines 9-11 indicate that the
+set is not yet complete. The triple represented by line 10 looks in
+its expanded form like this (see the <a href="#subsection-ntriples">N-Triples example</a>
+for the expanded form of the full example):</p> 
+<pre><code>&lt;http://example.org/bob#me&gt; &lt;http://xmlns.com/foaf/0.1/knows&gt; &lt;http://example.org/alice#me&gt; .</code>
+</pre>
+
+<p>Line 9 shows an example of a special kind of syntactic sugar. The triple
+should informally be read as &quot;Bob (is) a Person&quot;. The
+<code>a</code> predicate 
+is a shorthand for the property <code>rdf:type</code> which models the
+instance relation (see Table <a href="#table-rdf-schema">&quot;RDF Schema
+constructs&quot;</a>). The <code> a</code> shorthand is intended to match the human
+intuition about <code>rdf:type</code>. </p><p>
+
+</p><p>In line 11 we see an example of a literal, in this case a date. The
+datatype is appended to the literal through a <code>^^</code> delimiter. The date
+representation follows the conventions of the XML Schema datatype
+<a href="http://www.w3.org/TR/xmlschema11-2/#date">date</a>.</p>
+
+<p>Because string literals are so ubiquitous Turtle allows the user to
+omit the datatype when writing a string literal. Thus, <code>&quot;Leonardo
+da Vinci&quot;</code> in line 16 is equivalent to
+<code>&quot;Leonardo da Vinci&quot;^^xsd:string</code>. </p>
+
+<p>The figure below shows the triples resulting from this example.</p>
+
+<figure id="fig-abstract-graph-single">
+  <img alt="Triples resulting from the Turtle example" src="abstract-graph-single.jpg" />
+  <figcaption>Fig. <span class="figno">3</span> <span class="fig-title">Triples resulting from the Turtle example. </span></figcaption>
+</figure>
+
+<div class="issue"><div class="issue-title" aria-level="3" role="heading" id="h_issue_6"><span>Issue 6</span></div><p class="">TODO: proper redesign of figure</p></div>
+
+<p>In case of language-tagged strings the tag
+appears directly after the string, separated by a <code>@</code>
+symbol, e.g. <code>&quot;Léonard de Vinci&quot;@fr</code>.</p>
+
+<div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_11"><span>Note</span></div><p class="">For technical reasons the datatype of language-tagged
+strings is not <code>xsd:string</code> but
+<code>rdf:langString</code>. The
+datatype of language-tagged strings is never specified explicitly
+in Turtle.</p></div>
+
+<p>Below is sample Turtle syntax for blank nodes, using the
+earlier cypress-tree example:</p>  
+
+<div class="example"><div class="example-title"><span>Example 4</span></div><pre class="example">@prefix dbpedia: &lt;http://dbpedia.org/resource/&gt; .
[email protected] lio: &lt;http://purl.org/net/lio#&gt; . 
+
+dbpedia:Mona_Lisa lio:shows _:x .
+_:x a dbpedia:Cypress .</pre></div>
+
+<p>The term <code>_:x</code> is a blank node. It represents some
+unamed tree depicted in the Mona Lisa painting and belonging to the
+&quot;Cypress&quot; class. </p>
+
+<p>The above is by no means a full account of the Turtle syntax. For
+more details about the syntax of Turtle the reader is referred to the
+Turtle document [<cite><a class="bibref" href="#bib-TURTLE">TURTLE</a></cite>].</p>
+
+</section>
+
+    <section id="subsection-trig" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+
+      <h3 aria-level="2" role="heading" id="h3_subsection-trig"><span class="secno">5.2 </span>TriG</h3>
+
+      <p>The syntax of Turtle supports only the specification of single
+      graphs without a means for &quot;naming&quot; them. TriG [<cite><a class="bibref" href="#bib-TRIG">TRIG</a></cite>] is an
+      extension to the Turtle syntax enabling the specification of
+      multiple graphs.</p>
+
+<div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_12"><span>Note</span></div><p class="">In RDF 1.1 any legal Turtle document is a legal TriG
+document. One could view it as one language. The names Turtle and TriG
+still exist for historical reasons.</p></div> 
+
+      <p>The <a href="#subsection-multiple-graphs">multiple-graphs version of our example</a>
+      can be specified in TriG as follows:</p>
+
+      <div class="example"><div class="example-title"><span>Example 5</span></div><pre id="trig-example" class="example">01    @base &lt;http://example.org/&gt; .
+02    @prefix foaf: &lt;http://xmlns.com/foaf/0.1/&gt; .
+03    @prefix xsd: &lt;http://www.w3.org/2001/XMLSchema#&gt; .
+04    @prefix schema: &lt;http://schema.org/&gt; .
+05    @prefix dcterms: &lt;http://purl.org/dc/terms/&gt; .
+06    @prefix wd: &lt;http://www.wikidata.org/entity/&gt; .
+07    
+08    &lt;http://example.org/bob&gt;
+09      {
+10        &lt;bob#me&gt;
+11            a foaf:Person ;
+12            foaf:knows &lt;alice#me&gt; ;
+13            schema:birthDate &quot;1990-07-04&quot;^^xsd:date ;
+14            foaf:topic_interest wd:Q12418 .
+15      }
+16
+17    &lt;https://www.wikidata.org/wiki/Special:EntityData/Q12418&gt;
+18      {
+19        &lt;http://dbpedia.org/resource/Leonardo_da_Vinci&gt;
+20            a foaf:Person ;
+21            foaf:name &quot;Leonardo da Vinci&quot; .
+22    
+23        wd:Q12418
+24            dcterms:creator &lt;http://dbpedia.org/resource/Leonardo_da_Vinci&gt; .
+25    
+26        &lt;http://data.europeana.eu/item/04802/243FA8618938F4117025F17A8B813C5F9AA4D619&gt;
+27           dcterms:subject wd:Q12418 .
+28      }
+29
+30    &lt;http://example.org/bob&gt;
+31        dcterms:publisher &lt;http://example.org&gt; ;
+32        dcterms:rights &lt;http://creativecommons.org/licenses/by/3.0/&gt; .</pre></div>
+
+    <p>This RDF dataset contains two named graphs. Lines 8 and 16 list
+    the names of these two graphs. The triples in the named graph are
+    placed in between matching curly braces (lines 9 &amp; 15, 18 &amp;
+    28). Optionally you can precede the graph name with the keyword
+    <code>GRAPH</code>. This may improve readability, but it is mainly
+    introduced for alignment with SPARQL Update [<cite><a class="bibref" href="#bib-SPARQL11-OVERVIEW">SPARQL11-OVERVIEW</a></cite>]. </p>
+
+    <p>The syntax of the triples and of the directives at the top conforms to
+    the Turtle syntax.</p>
+
+    <p>The two triples specified on lines 30-32 are not part of any
+    named graph. Together they form the default graph of this RDF
+    dataset.</p>
+
+    <p>The figure below shows the triples resulting from this example.</p>
+
+    <figure id="fig-abstract-graph-multiple">
+      <img alt="Triples resulting from the TriG example" src="http://www.example.org/abstract-graph-multiple" />
+      <figcaption>Fig. <span class="figno">4</span> <span class="fig-title">Triples resulting from the TriG example</span></figcaption>
+    </figure>
+
+    <div class="issue"><div class="issue-title" aria-level="3" role="heading" id="h_issue_7"><span>Issue 7</span></div><p class="">TODO: include figure</p></div>
+
+    </section>
+
+    <section id="subsection-other-syntaxes" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+
+    <h3 aria-level="2" role="heading" id="h3_subsection-other-syntaxes"><span class="secno">5.3 </span>Other concrete syntaxes for RDF</h3>
+
+    <p>Next to Turtle/TriG there are a number of other concrete syntaxes
+    for RDF data. These syntaxes were developed to cater for specific
+    application and/or usage needs. The examples given for each of
+    these syntaxes correspond to the same graph (i.e., the same set of
+    triples) as the Turtle example (in the case of a single graph, see <a href="#fig-abstract-graph-single" class="fig-ref">Fig. 4</a>)or the TriG example
+    (in the case of multiple graphs, see <a href="#fig-abstract-graph-multiple" class="fig-ref">Fig. 5</a>). </p>
+
+    <dl>
+      <dt>RDFa</dt>
+      <dd>RDFa [<cite><a class="bibref" href="#bib-RDFA-PRIMER">RDFA-PRIMER</a></cite>] (<a href="#rdfa-example">single-graph example</a>) 
+      can be used to embed RDF data within
+      HTML documents. This enables, for example, search engines to aggregate
+      this data when crawling the web and use it to enrich search
+      results (see, e.g., 
+      <a href="http://schema.org">schema.org</a> 
+      and <a href="https://support.google.com/webmasters/answer/99170?hl=en">Rich
+      Snippets</a>). 
+      </dd>
+
+      <dt>JSON-LD</dt>
+      <dd>JSON-LD [<cite><a class="bibref" href="#bib-JSON-LD">JSON-LD</a></cite>] (<a href="#json-ld-example-single">single-graph
+      example</a>, <a href="#json-ld-example-multiple">multiple-graphs example</a>)  
+      provides a JSON syntax for RDF graphs and datasets.
+      JSON-LD can be used to transform JSON documents to RDF with
+      minimal changes. JSON-LD offers universal identifiers for
+      JSON objects, a mechanism in which a JSON document can refer to 
+      an object described in another JSON document elsewhere on the
+      Web, as well as datatype and language handling. JSON-LD
+      also provides a way to serialize RDF datasets 
+      through the use of the <code>@graph</code> keyword. </dd>
+
+      <dt>N-Triples</dt>
+      <dd>N-Triples [<cite><a class="bibref" href="#bib-N-TRIPLES">N-TRIPLES</a></cite>] ( <a href="#n-triples-example">single-graph example</a>)
+      provides a simple line-based, plain text way for serializing RDF
+      graphs. Each line represents 
+      an RDF triple. Its subject, predicate and object are separated
+      by white space. N-Triples is often used for RDF examples,
+      exchanging large RDF datasets, and processing large RDF graphs 
+      with line-oriented text processing tools. </dd>
+
+      <dt>N-Quads</dt>
+      <dd>N-Quads [<cite><a class="bibref" href="#bib-N-QUADS">N-QUADS</a></cite>] (<a href="#n-quads-example">multiple-graphs example</a>) is
+      a simple extension to N-Triples enabling the exchange of RDF
+      datasets. N-Quads adds a fourth 
+      element to each line, capturing the graph IRI of the triple
+      described on that line. </dd>
+
+      <dt>RDF/XML</dt>
+      <dd>RDF/XML [<cite><a class="bibref" href="#bib-RDF-SYNTAX-GRAMMAR">RDF-SYNTAX-GRAMMAR</a></cite>] (<a href="#rdf-xml-example">single-graph example</a>)
+      provides an XML syntax for RDF
+      graphs. RDF/XML was the only normative syntax for RDF when RDF
+      1.0 was published in 2004. </dd>
+   </dl>
+
+   <p>For more information about these syntaxes consult the references.</p>
+
+   </section>
+</section>
+
+
+<section id="section-semantics" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+
+    
+<!--OddPage-->
+<h2 aria-level="1" role="heading" id="h2_section-semantics"><span class="secno">6. </span>Semantics of RDF Graphs</h2>
+   
+    <p>RDF is grounded in a formal model-theoretic semantics which is
+    specified in the RDF 
+    Semantics document [<cite><a class="bibref" href="#bib-RDF11-MT">RDF11-MT</a></cite>]. 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
+    example, consider the following two statements:</p>
+    <pre>    <code>ex:bob foaf:knows ex:alice .</code>
+    <code>rdfs:domain foaf:knows foaf:Person .</code>
+    </pre>
+    <p>The RDF Semantics document tell us that from this graph it is legal to
+    derive the following triple:</p>
+    <pre>    <code>ex:bob rdf:type foaf:Person .</code>
+   </pre>
+   
+   <div class="note"><div class="note-title" aria-level="2" role="heading" id="h_note_13"><span>Note</span></div><p class="">RDF Semantics distinguishes
+   a number of different &quot;entailment regimes&quot;. The derivation above is
+   an example of an RDF Schema entailment. For detailed
+   information about entailment regimes 
+   please consult the RDF Semantics document [<cite><a class="bibref" href="#bib-RDF11-MT">RDF11-MT</a></cite>]. </p></div> 
+
+   
+<!--
+   <p class="note">As we saw in the earlier <a
+   href="#section-rurtle-example">Turtle example</a> (line 9) we could have
+   used the shorthand <code>ex:bob a foaf:Person</code> for the example
+   above. </p>
+   -->
+
+   
+   <p>The semantics of RDF also tell us that the triple:</p>
+    <pre>   <code>ex:bob ex:age &quot;forty&quot;^^xsd:integer . </code>
+   </pre>
+   <p>leads to a logical inconsistency, because the literal does not
+    abide by the constraints defined for the XML Schema datatype <a href="http://www.w3.org/TR/xmlschema11-2/#integer">integer</a>.</p>
+
+   <div class="note"><div class="note-title" aria-level="2" role="heading" id="h_note_14"><span>Note</span></div><p class="">RDF tools may not recognize all datatypes. As a
+   minimum, tools are required to support the datatypes for string literals
+   and language-tagged literals.</p></div>
+
+   <p>Unlike many other data
+   modeling languages, RDF Schema allows considerble modelling
+   freedom. 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 &quot;classes&quot; and of &quot;instances&quot;. Therefore, RDF
+   semantics views the following graph as valid:</p>
+   <pre>   <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>The examples in this section are just meant to give the reader
+some feeling about what the RDF Semantics brings you. Please consult
+[<cite><a class="bibref" href="#bib-RDF11-MT">RDF11-MT</a></cite>] for a complete description.</p>
+
+   </section>
+
+   <section id="section-data" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+
+    
+<!--OddPage-->
+<h2 aria-level="1" role="heading" id="h2_section-data"><span class="secno">7. </span>RDF Data</h2>
+
+    <p>RDF allows you to combine triples from any source into a graph
+    and process it as legal RDF. A large amount of RDF data is
+    available as part of the Linked 
+    Data [<cite><a class="bibref" href="#bib-LINKED-DATA">LINKED-DATA</a></cite>] cloud. Datasets are being published and
+    interlinked on the Web using RDF, and many of them offer a
+    querying facility through SPARQL [<cite><a class="bibref" href="#bib-SPARQL11-OVERVIEW">SPARQL11-OVERVIEW</a></cite>]. 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 
+      <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><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
+    <a href="http://datahub.io/organization/lodcloud">datahub.io</a>.</p>
+
+    <p>A number of vocabulary terms have become popular for
+    recording links between RDF data sources. An example is the
+    <code>sameAs</code> property provided by the OWL vocabulary. This
+    property can be used to indicate that two IRIs point in fact 
+    to the same resource. This is useful because different publishers
+    may use different identifiers to denote the same thing. For
+    example, VIAF (see above) also has an IRI denoting Leonardo da
+    Vinci. With the help of <code>owl:sameAs</code> we can record this
+    information:</p>
+
+    <div class="example"><div class="example-title"><span>Example 6</span></div><pre class="example">&lt;http://dbpedia.org/resource/Leonardo_da_Vinci&gt;
+    owl:sameAs &lt;http://viaf.org/viaf/24604287/&gt; .</pre></div>
+
+    <p>Such links can be deployed by RDF data-processing
+    software. </p>
+
+    </section>
+
+    <section id="section-conclusion" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    
+<!--OddPage-->
+<h2 aria-level="1" role="heading" id="h2_section-conclusion"><span class="secno">8. </span>More Information</h2>
+    
+    <p>This concludes our brief introduction into RDF. Please consult
+    the references to get more detailed information. You might also
+    want to take a look at the <a href="http://www.w3.org/standards/semanticweb/data"><abbr title="World Wide Web Consortium">W3C</abbr> Linked Data page</a>. </p>
+
+    <div class="issue"><div class="issue-title" aria-level="2" role="heading" id="h_issue_8"><span>Issue 8</span></div><p class="">TODO: check whther this is the right place to
+    point to in <abbr title="World Wide Web Consortium">W3C</abbr> space.</p></div>
+    
+    </section>
+
+    <section class="appendix" id="section-Acknowledgments" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    
+<!--OddPage-->
+<h2 aria-level="1" role="heading" id="h2_section-Acknowledgments"><span class="secno">A. </span>Acknowledgments</h2>
+
+    <p>Antoine Isaac provided many examples, including the 
+    different syntactic forms. Pierre-Antoine Champin provided the
+    alternate JSON-LD example. Andrew Wood designed the graph
+    diagrams. We are grateful for the comments provided by (in
+    alphabetical order) Dan Brickley, Pierre-Antoine Champin, Pat
+    Hayes and David Wood. </p>
+  
+    <div class="issue"><div class="issue-title" aria-level="2" role="heading" id="h_issue_9"><span>Issue 9</span></div><p class="">Should we still inclue the 2004 acknowledgements,
+    given that the document is completely rewritten?</p></div>
+    
+<!--
+    <p>The RDF 2004 editors acknowledge the contributions from many
+    members of the RDF Core Working Group. Specific thanks are due to
+    Art Barstow, Dave Beckett, Dan Brickley, Ron Daniel, Ben
+    Hammersley, Martyn Horner, Graham Klyne, Sean Palmer, Patrick
+    Stickler, Aaron Swartz, Ralph Swick, and Garret Wilson who,
+    together with the many people who commented on earlier versions of
+    the Primer, provided valuable contributions to this document. 
+    In addition, this document contains a significant contribution from
+    Pat Hayes, Sergey Melnik, and Patrick Stickler, who led the
+    development of the RDF datatype facilities described in the RDF
+    family of specifications. </p>
+    -->
+
+  
+</section>
+
+<section id="changes" class="appendix" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+  
+<!--OddPage-->
+<h2 aria-level="1" role="heading" id="h2_changes"><span class="secno">B. </span>Changes</h2>
+
+  <dl>
+   <dt>Changes compared to 2004 version</dt>
+   <dd>The introduction contains a number of sentences from the
+   2004 document. For the rest the RDF 1.1 Primer is a completely
+   new document.</dd> 
+  </dl>
+</section>
+  
+<section class="appendix" id="section-other-syntaxes" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+
+   
+<!--OddPage-->
+<h2 aria-level="1" role="heading" id="h2_section-other-syntaxes"><span class="secno">C. </span>Examples of RDF syntaxes</h2>
+   
+<p>In Sec. <a href="#section-graph-syntax">&quot;Writing RDF Graphs&quot;</a> the
+different concrete syntaxes of RDF are briefly described. Examples are
+given only of the Turtle and TriG syntax. This appendix lists
+corresponding examples for the other syntaxes listed. The
+single-graph examples encode the same graph as the <a href="#turtle-example">Turtle 
+example</a>; the mutiple-graphs examples encode the same graph as the <a href="#trig-example">Trig
+example</a>. </p>
+
+
+      <section id="subsection-rdfa" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+   
+      <h3 aria-level="2" role="heading" id="h3_subsection-rdfa"><span class="secno">C.1 </span>RDFa</h3>
+
+      <p>Single-graph example:</p>
+
+      <div class="example"><div class="example-title"><span>Example 7</span></div><pre id="rdfa-example" class="example">01    &lt;div prefix=&quot;
+02      rdf: http://www.w3.org/1999/02/22-rdf-syntax-ns#
+03      foaf: http://xmlns.com/foaf/0.1/
+04      wd: http://www.wikidata.org/entity/
+05      dcterms: http://purl.org/dc/terms/
+06      xsd: http://www.w3.org/2001/XMLSchema#&quot;&gt;
+07        &lt;div typeof=&quot;foaf:Person&quot; about=&quot;http://example.org/bob#me&quot;&gt;
+08          &lt;p&gt;
+09            Bob knows &lt;a rel=&quot;foaf:knows&quot; href=&quot;http://example.org/alice#me&quot;&gt;Alice&lt;/a&gt;
+10            and was born on the &lt;span property=&quot;schema:birthDate&quot; datatype=&quot;xsd:date&quot;&gt;1990-07-04&lt;/span&gt;.
+11          &lt;/p&gt;
+12          &lt;p&gt;
+13            Bob is interested in &lt;a rel=&quot;foaf:topic_interest&quot; resource=&quot;wd:Q12418&quot;&gt;the Mona Lisa&lt;/a&gt;.
+14          &lt;/p&gt;
+15          &lt;div about=&quot;wd:Q12418&quot;&gt;
+16            The Mona Lisa was painted by &lt;a rel=&quot;dcterms:creator&quot; typeof=&quot;foaf:Person&quot; href=&quot;http://dbpedia.org/resource/Leonardo_da_Vinci&quot;&gt;&lt;span property=&quot;foaf:name&quot;&gt;Leonardo da Vinci&lt;/span&gt;&lt;/a&gt;
+17            and is the subject of the video &lt;a rev=&quot;dcterms:subject&quot; href=&quot;http://data.europeana.eu/item/04802/243FA8618938F4117025F17A8B813C5F9AA4D619&quot;&gt;'La Joconde à Washington'&lt;/a&gt;.
+18          &lt;/div&gt;
+19      &lt;/div&gt;
+20    &lt;/div&gt;</pre></div>
+
+    </section>
+
+    <section id="subsection-jsonld" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+
+      <h3 aria-level="2" role="heading" id="h3_subsection-jsonld"><span class="secno">C.2 </span>JSON-LD</h3>
+
+      Single-graph example:
+
+      <div class="example"><div class="example-title"><span>Example 8</span></div><pre id="json-ld-example-single" class="example">01    {
+02      &quot;@context&quot;: {
+03        &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;,
+04        &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
+05        &quot;schema&quot;: &quot;http://schema.org/&quot;,
+06        &quot;dcterms&quot;: &quot;http://purl.org/dc/terms/&quot;,
+07        &quot;wd&quot;: &quot;http://www.wikidata.org/entity/&quot;,
+08        &quot;@base&quot;: &quot;http://example.org/&quot;,
+09        &quot;subject_of&quot;: {&quot;@reverse&quot;: &quot;dcterms:subject&quot;}
+10      },
+11      &quot;@id&quot;: &quot;bob#me&quot;,
+12      &quot;@type&quot;: &quot;foaf:Person&quot;,
+13      &quot;schema:birthDate&quot;: {
+14        &quot;@value&quot;: &quot;1990-07-04&quot;,
+15        &quot;@type&quot;: &quot;xsd:date&quot;
+16      },
+17      &quot;foaf:knows&quot;: {
+18        &quot;@id&quot;: &quot;alice#me&quot;
+19      },
+20      &quot;foaf:topic_interest&quot;: {
+21        &quot;@id&quot;: &quot;wd:Q12418&quot;,
+22        &quot;subject_of&quot;: {
+23            &quot;@id&quot;: &quot;http://data.europeana.eu/item/04802/243FA8618938F4117025F17A8B813C5F9AA4D619&quot;
+24        },
+25        &quot;dcterms:creator&quot;: {
+26          &quot;@id&quot;: &quot;http://dbpedia.org/resource/Leonardo_da_Vinci&quot;,
+27          &quot;@type&quot;: &quot;foaf:Person&quot;,
+28          &quot;foaf:name&quot;: &quot;Leonardo da Vinci&quot;
+29        }
+30      }
+31    }</pre></div>
+
+     <p>Multiple-graphs example:</p>
+
+      <div class="example"><div class="example-title"><span>Example 9</span></div><pre id="json-ld-example-multiple" class="example">01    {
+02      &quot;@context&quot;: {
+03        &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;,
+04        &quot;schema&quot;: &quot;http://schema.org/&quot;,
+05        &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
+06        &quot;dcterms&quot;: &quot;http://purl.org/dc/terms/&quot;
+07      },
+08      &quot;@graph&quot;: [
+09        {
+10          &quot;@id&quot;: &quot;http://example.org/bob&quot;,
+11          &quot;@graph&quot;: [
+12            {
+13              &quot;@id&quot;: &quot;http://example.org/bob#me&quot;,
+14              &quot;@type&quot;: &quot;foaf:Person&quot;,
+15              &quot;foaf:knows&quot;: {
+16                &quot;@id&quot;: &quot;http://example.org/alice#me&quot;
+17              },
+18              &quot;foaf:topic_interest&quot;: {
+19                &quot;@id&quot;: &quot;http://www.wikidata.org/entity/Q12418&quot;
+20              },
+21              &quot;schema:birthDate&quot;: {
+22                &quot;@value&quot;: &quot;1990-07-04&quot;,
+23                &quot;@type&quot;: &quot;xsd:date&quot;
+24              }
+25            }
+26          ],
+27          &quot;dcterms:publisher&quot;: {
+28            &quot;@id&quot;: &quot;http://example.org&quot;
+29          },
+30          &quot;dcterms:rights&quot;: {
+31            &quot;@id&quot;: &quot;http://creativecommons.org/licenses/by/3.0/&quot;
+32          }
+33        },
+34        {
+35          &quot;@id&quot;: &quot;https://www.wikidata.org/wiki/Special:EntityData/Q12418&quot;,
+36          &quot;@graph&quot;: [
+37            {
+38              &quot;@id&quot;: &quot;http://data.europeana.eu/item/04802/243FA8618938F4117025F17A8B813C5F9AA4D619&quot;,
+39              &quot;dcterms:subject&quot;: {
+40                &quot;@id&quot;: &quot;http://www.wikidata.org/entity/Q12418&quot;,
+41                &quot;dcterms:creator&quot;: {
+42                  &quot;@id&quot;: &quot;http://dbpedia.org/resource/Leonardo_da_Vinci&quot;,
+43                  &quot;@type&quot;: &quot;foaf:Person&quot;,
+44                  &quot;foaf:name&quot;: &quot;Leonardo da Vinci&quot;
+45                }
+46              }
+47            }
+48          ]
+49        }
+50      ]
+51    }</pre></div>
+
+<p>Below is an alternate single-graph example with more idiomatic
+JSON data, at the cost of a more elaborate definition of
+<code>@context</code>. </p>
+
+<div class="issue"><div class="issue-title" aria-level="3" role="heading" id="h_issue_10"><span>Issue 10</span></div><p class="">Should we include this alternative example?</p></div>
+
+<div class="example"><div class="example-title"><span>Example 10</span></div><pre class="example">01  {
+02    &quot;@context&quot;: {
+03      &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;,
+04      &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
+05      &quot;schema&quot;: &quot;http://schema.org/&quot;,
+06      &quot;dcterms&quot;: &quot;http://purl.org/dc/terms/&quot;,
+07      &quot;wd&quot;: &quot;http://www.wikidata.org/entity/&quot;,
+08      &quot;@base&quot;: &quot;http://example.org/&quot;,
+09
+10      &quot;uri&quot;: &quot;@id&quot;,
+11      &quot;type&quot;: &quot;@type&quot;,
+12      &quot;Person&quot;: &quot;foaf:Person&quot;,
+13      &quot;born&quot;: {
+14          &quot;@id&quot;: &quot;schema:birthDate&quot;,
+15          &quot;@type&quot;: &quot;xsd:date&quot;
+16      },
+17      &quot;friends&quot;: {
+18          &quot;@id&quot;: &quot;foaf:knows&quot;,
+19          &quot;@type&quot;: &quot;@id&quot;
+20      },
+21      &quot;interest&quot;: &quot;http://xmlns.com/foaf/0.1/topic_interest&quot;,
+22      &quot;subject_of&quot;: {
+23          &quot;@reverse&quot;: &quot;dcterms:subject&quot;,
+24          &quot;@type&quot;: &quot;@id&quot;
+25      },
+26      &quot;creator&quot;: &quot;dc:creator&quot;,
+27      &quot;name&quot;: &quot;foaf:name&quot;
+28    },
+29
+30    &quot;uri&quot;: &quot;bob#me&quot;,
+31    &quot;type&quot;: &quot;Person&quot;,
+32    &quot;born&quot;: &quot;1990-07-04&quot;,
+33    &quot;friends&quot;: [&quot;alice#me&quot;],
+34    &quot;interest&quot;: [
+35      {
+36          &quot;uri&quot;: &quot;wd:Q12418&quot;,
+37          &quot;subject_of&quot;: &quot;http://data.europeana.eu/item/04802/243FA8618938F4117025F17A8B813C5F9AA4D619&quot;,
+38          &quot;creator&quot;: {
+39              &quot;uri&quot;: &quot;http://dbpedia.org/resource/Leonardo_da_Vinci&quot;,
+40              &quot;type&quot;: &quot;Person&quot;,
+41              &quot;name&quot;: &quot;Leonardo da Vinci&quot;
+42          }
+43      }
+44    ]
+45  }</pre></div>
+
+
+    </section>
+
+
+<section id="subsection-ntriples" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+
+      <h3 aria-level="2" role="heading" id="h3_subsection-ntriples"><span class="secno">C.3 </span>N-Triples</h3>
+
+      <p>Single-graph example: </p>
+
+      <div class="example"><div class="example-title"><span>Example 11</span></div><pre id="n-triples-example" class="example">01    &lt;http://example.org/bob#me&gt; &lt;http://www.w3.org/1999/02/22-rdf-syntax-ns#type&gt; &lt;http://xmlns.com/foaf/0.1/Person&gt;.
+02    &lt;http://example.org/bob#me&gt; &lt;http://xmlns.com/foaf/0.1/knows&gt; &lt;http://example.org/alice#me&gt;.
+03    &lt;http://example.org/bob#me&gt; &lt;http://schema.org/birthDate&gt; &quot;1990-07-04&quot;^^&lt;http://www.w3.org/2001/XMLSchema#date&gt;.
+04    &lt;http://example.org/bob#me&gt; &lt;http://xmlns.com/foaf/0.1/topic_interest&gt; &lt;http://www.wikidata.org/entity/Q12418&gt;.
+05    &lt;http://dbpedia.org/resource/Leonardo_da_Vinci&gt; &lt;http://www.w3.org/1999/02/22-rdf-syntax-ns#type&gt; &lt;http://xmlns.com/foaf/0.1/Person&gt;.
+06    &lt;http://dbpedia.org/resource/Leonardo_da_Vinci&gt; &lt;http://xmlns.com/foaf/0.1/name&gt; &quot;Leonardo da Vinci&quot;.
+07    &lt;http://www.wikidata.org/entity/Q12418&gt; &lt;http://purl.org/dc/terms/creator&gt; &lt;http://dbpedia.org/resource/Leonardo_da_Vinci&gt;.
+08    &lt;http://data.europeana.eu/item/04802/243FA8618938F4117025F17A8B813C5F9AA4D619&gt; &lt;http://purl.org/dc/terms/subject&gt; &lt;http://www.wikidata.org/entity/Q12418&gt;.</pre></div>
+
+     </section>
+
+    <section id="subsection-nquads" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+
+      <h3 aria-level="2" role="heading" id="h3_subsection-nquads"><span class="secno">C.4 </span>N-Quads</h3>
+
+<p>Multiple-graph example:</p>
+
+      <div class="example"><div class="example-title"><span>Example 12</span></div><pre id="n-quads-example" class="example">01    &lt;http://example.org/bob#me&gt; &lt;http://www.w3.org/1999/02/22-rdf-syntax-ns#type&gt; &lt;http://xmlns.com/foaf/0.1/Person&gt; &lt;http://example.org/bob&gt; .
+02    &lt;http://example.org/bob#me&gt; &lt;http://xmlns.com/foaf/0.1/knows&gt; &lt;http://example.org/alice#me&gt; &lt;http://example.org/bob&gt; .
+03    &lt;http://example.org/bob#me&gt; &lt;http://schema.org/birthDate&gt; &quot;1990-07-04&quot;^^&lt;http://www.w3.org/2001/XMLSchema#date&gt; &lt;http://example.org/bob&gt; .
+04    &lt;http://example.org/bob#me&gt; &lt;http://xmlns.com/foaf/0.1/topic_interest&gt; &lt;http://www.wikidata.org/entity/Q12418&gt; &lt;http://example.org/bob&gt; .
+05    &lt;http://dbpedia.org/resource/Leonardo_da_Vinci&gt; &lt;http://www.w3.org/1999/02/22-rdf-syntax-ns#type&gt; &lt;http://xmlns.com/foaf/0.1/Person&gt; &lt;https://www.wikidata.org/wiki/Special:EntityData/Q12418&gt; .
+06    &lt;http://dbpedia.org/resource/Leonardo_da_Vinci&gt; &lt;http://xmlns.com/foaf/0.1/name&gt; &quot;Leonardo da Vinci&quot; &lt;https://www.wikidata.org/wiki/Special:EntityData/Q12418&gt; .
+07    &lt;http://www.wikidata.org/entity/Q12418&gt; &lt;http://purl.org/dc/terms/creator&gt; &lt;http://dbpedia.org/resource/Leonardo_da_Vinci&gt; &lt;https://www.wikidata.org/wiki/Special:EntityData/Q12418&gt; .
+08    &lt;http://data.europeana.eu/item/04802/243FA8618938F4117025F17A8B813C5F9AA4D619&gt; &lt;http://purl.org/dc/terms/subject&gt; &lt;http://www.wikidata.org/entity/Q12418&gt; &lt;https://www.wikidata.org/wiki/Special:EntityData/Q12418&gt; .
+09    &lt;http://example.org/bob&gt; &lt;http://purl.org/dc/terms/publisher&gt; &lt;http://example.org&gt; .
+10    &lt;http://example.org/bob&gt; &lt;http://purl.org/dc/terms/rights&gt; &lt;http://creativecommons.org/licenses/by/3.0/&gt; .</pre></div>
+
+    </section>
+
+    <section id="subsection-rdf-xml" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+
+    <h3 aria-level="2" role="heading" id="h3_subsection-rdf-xml"><span class="secno">C.5 </span>RDF/XML</h3>
+
+    <p>Single-graph example:</p>
+
+      <div class="example"><div class="example-title"><span>Example 13</span></div><pre id="rdf-xml-example" class="example">01    &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
+02    &lt;rdf:RDF
+03       xmlns:dcterms=&quot;http://purl.org/dc/terms/&quot;
+04       xmlns:foaf=&quot;http://xmlns.com/foaf/0.1/&quot;
+05       xmlns:rdf=&quot;http://www.w3.org/1999/02/22-rdf-syntax-ns#&quot;
+06       xmlns:schema=&quot;http://schema.org/&quot;
+07       xmlns:wd=&quot;http://www.wikidata.org/entity/&quot;
+08       xmlns:xsd=&quot;http://www.w3.org/2001/XMLSchema#&quot;&gt;
+09      &lt;foaf:Person rdf:about=&quot;http://example.org/bob#me&quot;&gt;
+10        &lt;schema:birthDate rdf:datatype=&quot;http://www.w3.org/2001/XMLSchema#date&quot;&gt;1990-07-04&lt;/schema:birthDate&gt;
+11        &lt;foaf:knows rdf:resource=&quot;http://example.org/alice#me&quot;/&gt;
+12        &lt;foaf:topic_interest rdf:resource=&quot;http://www.wikidata.org/entity/Q12418&quot;/&gt;
+13      &lt;/foaf:Person&gt;
+14      &lt;foaf:Person rdf:about=&quot;http://dbpedia.org/resource/Leonardo_da_Vinci&quot;&gt;
+15        &lt;foaf:name&gt;Leonardo da Vinci&lt;/foaf:name&gt;
+16      &lt;/foaf:Person&gt;
+17      &lt;rdf:Description rdf:about=&quot;http://www.wikidata.org/entity/Q12418&quot;&gt;
+18        &lt;dcterms:creator rdf:resource=&quot;http://dbpedia.org/resource/Leonardo_da_Vinci&quot;/&gt;
+19      &lt;/rdf:Description&gt;
+20      &lt;rdf:Description rdf:about=&quot;http://data.europeana.eu/item/04802/243FA8618938F4117025F17A8B813C5F9AA4D619&quot;&gt;
+21        &lt;dcterms:subject rdf:resource=&quot;http://www.wikidata.org/entity/Q12418&quot;/&gt;
+22      &lt;/rdf:Description&gt;
+23    &lt;/rdf:RDF&gt;</pre></div>
+
+    </section>
+    </section>
+   
+    <section id="references" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter"></section>
+
+  
+
+<section class="appendix" id="references" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+<!--OddPage-->
+<h2 aria-level="1" role="heading" id="h2_references"><span class="secno">D. </span>References</h2><section id="normative-references" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter"><h3 aria-level="2" role="heading" id="h3_normative-references"><span class="secno">D.1 </span>Normative references</h3><dl class="bibliography" about=""><dt id="bib-JSON-LD">[JSON-LD]</dt><dd rel="dcterms:requires">Manu Sporny, Gregg Kellogg, Markus Lanthaler, Editors. <cite><a href="http://www.w3.org/TR/2013/PR-json-ld-20131105/">JSON-LD 1.0</a>.</cite> 5 November 2013. W3C Proposed Recommendation. URL: <a href="http://www.w3.org/TR/2013/PR-json-ld-20131105/">http://www.w3.org/TR/2013/PR-json-ld-20131105/</a>. The latest edition is available at <a href="http://www.w3.org/TR/json-ld/">http://www.w3.org/TR/json-ld/</a>
+</dd><dt id="bib-RDF-SCHEMA">[RDF-SCHEMA]</dt><dd rel="dcterms:requires">Dan Brickley; Ramanathan Guha. <a href="http://www.w3.org/TR/rdf-schema"><cite>RDF Vocabulary Description Language 1.0: RDF Schema</cite></a>. 10 February 2004. W3C Recommendation. URL: <a href="http://www.w3.org/TR/rdf-schema">http://www.w3.org/TR/rdf-schema</a>
+</dd><dt id="bib-RDF11-CONCEPTS">[RDF11-CONCEPTS]</dt><dd rel="dcterms:requires">Richard Cyganiak, David Wood, Markus Lanthaler, Editors. <cite><a href="http://www.w3.org/TR/2013/CR-rdf11-concepts-20131105/">RDF 1.1 Concepts and Abstract Syntax.</a></cite> 5 November 2013. W3C Candidate Recommendation (work in progress). URL: <a href="http://www.w3.org/TR/2013/CR-rdf11-concepts-20131105/">http://www.w3.org/TR/2013/CR-rdf11-concepts-20131105/</a>. The latest edition is available at <a href="http://www.w3.org/TR/rdf11-concepts/">http://www.w3.org/TR/rdf11-concepts/</a>
+</dd><dt id="bib-RDF11-MT">[RDF11-MT]</dt><dd rel="dcterms:requires">Patrick J. Hayes, Peter F. Patel-Schneider, Editors. <cite><a href="http://www.w3.org/TR/2013/CR-rdf11-mt-20131105/">RDF 1.1 Semantics.</a></cite> 5 November 2013. W3C Candidate Recommendation (work in progress). URL: <a href="http://www.w3.org/TR/2013/CR-rdf11-mt-20131105/">http://www.w3.org/TR/2013/CR-rdf11-mt-20131105/</a>. The latest edition is available at <a href="http://www.w3.org/TR/rdf11-mt/">http://www.w3.org/TR/rdf11-mt/</a>
+</dd><dt id="bib-RDFA-PRIMER">[RDFA-PRIMER]</dt><dd rel="dcterms:requires">Ivan Herman; Ben Adida; Manu Sporny; Mark Birbeck. <a href="http://www.w3.org/TR/rdfa-primer/"><cite>RDFa 1.1 Primer - Second Edition</cite></a>. 22 August 2013. W3C Note. URL: <a href="http://www.w3.org/TR/rdfa-primer/">http://www.w3.org/TR/rdfa-primer/</a>
+</dd><dt id="bib-RFC3987">[RFC3987]</dt><dd rel="dcterms:requires">M. Dürst; M. Suignard. <a href="http://www.ietf.org/rfc/rfc3987.txt"><cite>Internationalized Resource Identifiers (IRIs)</cite></a>. January 2005. RFC. URL: <a href="http://www.ietf.org/rfc/rfc3987.txt">http://www.ietf.org/rfc/rfc3987.txt</a>
+</dd><dt id="bib-SPARQL11-OVERVIEW">[SPARQL11-OVERVIEW]</dt><dd rel="dcterms:requires">The W3C SPARQL Working Group. <a href="http://www.w3.org/TR/sparql11-overview/"><cite>SPARQL 1.1 Overview</cite></a>. 21 March 2013. W3C Recommendation. URL: <a href="http://www.w3.org/TR/sparql11-overview/">http://www.w3.org/TR/sparql11-overview/</a>
+</dd><dt id="bib-TRIG">[TRIG]</dt><dd rel="dcterms:requires">Gavin Carothers, Andy Seaborne, Editors. <cite><a href="http://www.w3.org/TR/2013/WD-trig-20130919/">TriG: RDF Dataset Language</a></cite>. 19 September 2013. W3C Candidate Recommendation (work in progress). URL: <a href="http://www.w3.org/TR/2013/WD-trig-20130919/">http://www.w3.org/TR/2013/WD-trig-20130919/</a>. The latest edition is available at <a href="http://www.w3.org/TR/trig/">http://www.w3.org/TR/trig/</a>
+</dd><dt id="bib-TURTLE">[TURTLE]</dt><dd rel="dcterms:requires">Eric Prud'hommeaux, Gavin Carothers, Editors. <cite><a href="http://www.w3.org/TR/2013/CR-turtle-20130219/">RDF 1.1 Turtle: Terse RDF Triple Language.</a></cite> 19 February 2013. W3C Candidate Recommendation (work in progress). URL: <a href="http://www.w3.org/TR/2013/CR-turtle-20130219/">http://www.w3.org/TR/2013/CR-turtle-20130219/</a>. The latest edition is available at <a href="http://www.w3.org/TR/turtle/">http://www.w3.org/TR/turtle/</a>
+</dd></dl></section><section id="informative-references" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter"><h3 aria-level="2" role="heading" id="h3_informative-references"><span class="secno">D.2 </span>Informative references</h3><dl class="bibliography" about=""><dt id="bib-LINKED-DATA">[LINKED-DATA]</dt><dd rel="dcterms:references">Tim Berners-Lee. <cite><a href="http://www.w3.org/DesignIssues/LinkedData.html">Linked Data</a></cite>. Personal View, imperfect but published. URL: <a href="http://www.w3.org/DesignIssues/LinkedData.html">http://www.w3.org/DesignIssues/LinkedData.html</a>
+</dd><dt id="bib-N-QUADS">[N-QUADS]</dt><dd rel="dcterms:references">Gavin Carothers, Editor. <cite><a href="http://www.w3.org/TR/2013/CR-n-quads-20131105/">RDF 1.1 N-Quads</a></cite>. 5 November 2013. W3C Candidate Recommendation (work in progress). URL: <a href="http://www.w3.org/TR/2013/CR-n-quads-20131105/">http://www.w3.org/TR/2013/CR-n-quads-20131105/</a>. The latest edition is available at <a href="http://www.w3.org/TR/n-quads/">http://www.w3.org/TR/n-quads/</a>
+</dd><dt id="bib-N-TRIPLES">[N-TRIPLES]</dt><dd rel="dcterms:references">Gavin Carothers, Editor. <cite><a href="http://www.w3.org/TR/2013/CR-n-triples-20131105/">RDF 1.1 N-Triples</a></cite>. 5 November 2013. W3C Candidate Recommendation (work in progress). URL: <a href="http://www.w3.org/TR/2013/CR-n-triples-20131105/">http://www.w3.org/TR/2013/CR-n-triples-20131105/</a>. The latest edition is available at <a href="http://www.w3.org/TR/n-triples/">http://www.w3.org/TR/n-triples/</a>
+</dd><dt id="bib-OWL2-OVERVIEW">[OWL2-OVERVIEW]</dt><dd rel="dcterms:references">W3C OWL Working Group. <a href="http://www.w3.org/TR/owl2-overview/"><cite>OWL 2 Web Ontology Language Document Overview (Second Edition)</cite></a>. 11 December 2012. W3C Recommendation. URL: <a href="http://www.w3.org/TR/owl2-overview/">http://www.w3.org/TR/owl2-overview/</a>
+</dd><dt id="bib-RDF-SYNTAX-GRAMMAR">[RDF-SYNTAX-GRAMMAR]</dt><dd rel="dcterms:references">Dave Beckett. <a href="http://www.w3.org/TR/rdf-syntax-grammar"><cite>RDF/XML Syntax Specification (Revised)</cite></a>. 10 February 2004. W3C Recommendation. URL: <a href="http://www.w3.org/TR/rdf-syntax-grammar">http://www.w3.org/TR/rdf-syntax-grammar</a>
+</dd></dl></section></section></body></html>
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