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+
+<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:public-rdf-comments@w3.org">public-rdf-comments@w3.org</a>
+ (<a href="mailto:public-rdf-comments-request@w3.org?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 "International Resource Identifier". See Sec. <a href="#subsection-IRI">"IRI"</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 ("RDF Concepts and Abstract Syntax")
+ [<cite><a class="bibref" href="#bib-RDF11-CONCEPTS">RDF11-CONCEPTS</a></cite>]</li>
+ <li>A document describing the formal model-theoretic semantics
+ of RDF ("RDF Semantics") [<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> <subject> <predicate> <object>
+ </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 "resource"?</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"><Bob> <is a> <person>.
+<Bob> <is a friend of> <Alice>.
+<Bob> <is born on> <the 4th of July 1990>.
+<Bob> <is interested in> <the Mona Lisa>.
+<The Mona Lisa> <was created by> <Leonardo da Vinci>.
+<The video 'La Joconde à Washington'> <is about> <the Mona Lisa></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 "abstract syntax", 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 "International Resource
+ Identifier". 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 "Mona Lisa" 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">"RDF vocabularies"</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 "La Joconde", dates such as "the 4th of July, 1990"
+ and numbers such as "3.14159".
+ 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 "Léonard de Vinci" could
+ be associated with the "fr" language tag and "李奥纳多·达·文西"
+ with the "zh" 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
+ "plain literal" with no datatype. This feature has been removed, as the
+ distinction between "plain" 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">"blank
+ nodes"</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> <Bob> <is a> <person>.
+ <Bob> <is a friend of> <Alice>.
+ <Bob> <is born on> <the 4th of July 1990>.
+ <Bob> <is interested in> <the Mona Lisa>.
+ </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 "graph name" 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 "graph name" 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> <Leonardo da Vinci> <is the creator of> <the Mona Lisa>.
+ <The video 'La Joconde à Washington'> <is about> <the Mona Lisa>
+ </pre>
+
+ <p>We can then write down triples that include a graph name,
+ for example:</p>
+
+ <pre> <http://example.org/bob> <is published by> <http://example.org>.
+ <http://example.org/bob> <has license> <http://creativecommons.org/licenses/by/3.0/>.
+ </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">"Trig syntax"</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">"Writing RDF Graphs"</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"><Person> <<strong>type</strong>> <Class>
+<is a friend of> <<strong>type</strong>> <Property>
+<is a friend of> <<strong>domain</strong>> <Person>
+<is a friend of> <<strong>range</strong>> <Person>
+<is a good friend of> <<strong>subPropertyOf</strong>> <is a friend of></pre></div>
+
+<p>One of first RDF vocabularies used worldwide was the
+<a href="http://www.foaf-project.org/">"Friend of a Friend"</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 "creator", "publisher" and "title".</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">"RDF syntax
+ examples"</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 <http://example.org/> .
+02 @prefix foaf: <http://xmlns.com/foaf/0.1/> .
+03 @prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
+04 @prefix schema: <http://schema.org/> .
+05 @prefix dcterms: <http://purl.org/dc/terms/> .
+06 @prefix wd: <http://www.wikidata.org/entity/> .
+07
+08 <bob#me>
+09 a foaf:Person ;
+10 foaf:knows <alice#me> ;
+11 schema:birthDate "1990-07-04"^^xsd:date ;
+12 foaf:topic_interest wd:Q12418 .
+13
+14 <http://dbpedia.org/resource/Leonardo_da_Vinci>
+15 a foaf:Person ;
+16 foaf:name "Leonardo da Vinci" .
+17
+18 wd:Q12418
+19 dcterms:creator <http://dbpedia.org/resource/Leonardo_da_Vinci> .
+20
+21 <http://data.europeana.eu/item/04802/243FA8618938F4117025F17A8B813C5F9AA4D61set>
+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><></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><http://xmlns.com/foaf/0.1/Person></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><http://example.org/bob#me> <http://xmlns.com/foaf/0.1/knows> <http://example.org/alice#me> .</code>
+</pre>
+
+<p>Line 9 shows an example of a special kind of syntactic sugar. The triple
+should informally be read as "Bob (is) a Person". 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">"RDF Schema
+constructs"</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>"Leonardo
+da Vinci"</code> in line 16 is equivalent to
+<code>"Leonardo da Vinci"^^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>"Léonard de Vinci"@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: <http://dbpedia.org/resource/> .
+@prefix lio: <http://purl.org/net/lio#> .
+
+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
+"Cypress" 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 "naming" 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 <http://example.org/> .
+02 @prefix foaf: <http://xmlns.com/foaf/0.1/> .
+03 @prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
+04 @prefix schema: <http://schema.org/> .
+05 @prefix dcterms: <http://purl.org/dc/terms/> .
+06 @prefix wd: <http://www.wikidata.org/entity/> .
+07
+08 <http://example.org/bob>
+09 {
+10 <bob#me>
+11 a foaf:Person ;
+12 foaf:knows <alice#me> ;
+13 schema:birthDate "1990-07-04"^^xsd:date ;
+14 foaf:topic_interest wd:Q12418 .
+15 }
+16
+17 <https://www.wikidata.org/wiki/Special:EntityData/Q12418>
+18 {
+19 <http://dbpedia.org/resource/Leonardo_da_Vinci>
+20 a foaf:Person ;
+21 foaf:name "Leonardo da Vinci" .
+22
+23 wd:Q12418
+24 dcterms:creator <http://dbpedia.org/resource/Leonardo_da_Vinci> .
+25
+26 <http://data.europeana.eu/item/04802/243FA8618938F4117025F17A8B813C5F9AA4D619>
+27 dcterms:subject wd:Q12418 .
+28 }
+29
+30 <http://example.org/bob>
+31 dcterms:publisher <http://example.org> ;
+32 dcterms:rights <http://creativecommons.org/licenses/by/3.0/> .</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 & 15, 18 &
+ 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 "entailment regimes". 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 "forty"^^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 "classes" and of "instances". 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"><http://dbpedia.org/resource/Leonardo_da_Vinci>
+ owl:sameAs <http://viaf.org/viaf/24604287/> .</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">"Writing RDF Graphs"</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 <div prefix="
+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#">
+07 <div typeof="foaf:Person" about="http://example.org/bob#me">
+08 <p>
+09 Bob knows <a rel="foaf:knows" href="http://example.org/alice#me">Alice</a>
+10 and was born on the <span property="schema:birthDate" datatype="xsd:date">1990-07-04</span>.
+11 </p>
+12 <p>
+13 Bob is interested in <a rel="foaf:topic_interest" resource="wd:Q12418">the Mona Lisa</a>.
+14 </p>
+15 <div about="wd:Q12418">
+16 The Mona Lisa was painted by <a rel="dcterms:creator" typeof="foaf:Person" href="http://dbpedia.org/resource/Leonardo_da_Vinci"><span property="foaf:name">Leonardo da Vinci</span></a>
+17 and is the subject of the video <a rev="dcterms:subject" href="http://data.europeana.eu/item/04802/243FA8618938F4117025F17A8B813C5F9AA4D619">'La Joconde à Washington'</a>.
+18 </div>
+19 </div>
+20 </div></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 "@context": {
+03 "foaf": "http://xmlns.com/foaf/0.1/",
+04 "xsd": "http://www.w3.org/2001/XMLSchema#",
+05 "schema": "http://schema.org/",
+06 "dcterms": "http://purl.org/dc/terms/",
+07 "wd": "http://www.wikidata.org/entity/",
+08 "@base": "http://example.org/",
+09 "subject_of": {"@reverse": "dcterms:subject"}
+10 },
+11 "@id": "bob#me",
+12 "@type": "foaf:Person",
+13 "schema:birthDate": {
+14 "@value": "1990-07-04",
+15 "@type": "xsd:date"
+16 },
+17 "foaf:knows": {
+18 "@id": "alice#me"
+19 },
+20 "foaf:topic_interest": {
+21 "@id": "wd:Q12418",
+22 "subject_of": {
+23 "@id": "http://data.europeana.eu/item/04802/243FA8618938F4117025F17A8B813C5F9AA4D619"
+24 },
+25 "dcterms:creator": {
+26 "@id": "http://dbpedia.org/resource/Leonardo_da_Vinci",
+27 "@type": "foaf:Person",
+28 "foaf:name": "Leonardo da Vinci"
+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 "@context": {
+03 "foaf": "http://xmlns.com/foaf/0.1/",
+04 "schema": "http://schema.org/",
+05 "xsd": "http://www.w3.org/2001/XMLSchema#",
+06 "dcterms": "http://purl.org/dc/terms/"
+07 },
+08 "@graph": [
+09 {
+10 "@id": "http://example.org/bob",
+11 "@graph": [
+12 {
+13 "@id": "http://example.org/bob#me",
+14 "@type": "foaf:Person",
+15 "foaf:knows": {
+16 "@id": "http://example.org/alice#me"
+17 },
+18 "foaf:topic_interest": {
+19 "@id": "http://www.wikidata.org/entity/Q12418"
+20 },
+21 "schema:birthDate": {
+22 "@value": "1990-07-04",
+23 "@type": "xsd:date"
+24 }
+25 }
+26 ],
+27 "dcterms:publisher": {
+28 "@id": "http://example.org"
+29 },
+30 "dcterms:rights": {
+31 "@id": "http://creativecommons.org/licenses/by/3.0/"
+32 }
+33 },
+34 {
+35 "@id": "https://www.wikidata.org/wiki/Special:EntityData/Q12418",
+36 "@graph": [
+37 {
+38 "@id": "http://data.europeana.eu/item/04802/243FA8618938F4117025F17A8B813C5F9AA4D619",
+39 "dcterms:subject": {
+40 "@id": "http://www.wikidata.org/entity/Q12418",
+41 "dcterms:creator": {
+42 "@id": "http://dbpedia.org/resource/Leonardo_da_Vinci",
+43 "@type": "foaf:Person",
+44 "foaf:name": "Leonardo da Vinci"
+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 "@context": {
+03 "foaf": "http://xmlns.com/foaf/0.1/",
+04 "xsd": "http://www.w3.org/2001/XMLSchema#",
+05 "schema": "http://schema.org/",
+06 "dcterms": "http://purl.org/dc/terms/",
+07 "wd": "http://www.wikidata.org/entity/",
+08 "@base": "http://example.org/",
+09
+10 "uri": "@id",
+11 "type": "@type",
+12 "Person": "foaf:Person",
+13 "born": {
+14 "@id": "schema:birthDate",
+15 "@type": "xsd:date"
+16 },
+17 "friends": {
+18 "@id": "foaf:knows",
+19 "@type": "@id"
+20 },
+21 "interest": "http://xmlns.com/foaf/0.1/topic_interest",
+22 "subject_of": {
+23 "@reverse": "dcterms:subject",
+24 "@type": "@id"
+25 },
+26 "creator": "dc:creator",
+27 "name": "foaf:name"
+28 },
+29
+30 "uri": "bob#me",
+31 "type": "Person",
+32 "born": "1990-07-04",
+33 "friends": ["alice#me"],
+34 "interest": [
+35 {
+36 "uri": "wd:Q12418",
+37 "subject_of": "http://data.europeana.eu/item/04802/243FA8618938F4117025F17A8B813C5F9AA4D619",
+38 "creator": {
+39 "uri": "http://dbpedia.org/resource/Leonardo_da_Vinci",
+40 "type": "Person",
+41 "name": "Leonardo da Vinci"
+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 <http://example.org/bob#me> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://xmlns.com/foaf/0.1/Person>.
+02 <http://example.org/bob#me> <http://xmlns.com/foaf/0.1/knows> <http://example.org/alice#me>.
+03 <http://example.org/bob#me> <http://schema.org/birthDate> "1990-07-04"^^<http://www.w3.org/2001/XMLSchema#date>.
+04 <http://example.org/bob#me> <http://xmlns.com/foaf/0.1/topic_interest> <http://www.wikidata.org/entity/Q12418>.
+05 <http://dbpedia.org/resource/Leonardo_da_Vinci> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://xmlns.com/foaf/0.1/Person>.
+06 <http://dbpedia.org/resource/Leonardo_da_Vinci> <http://xmlns.com/foaf/0.1/name> "Leonardo da Vinci".
+07 <http://www.wikidata.org/entity/Q12418> <http://purl.org/dc/terms/creator> <http://dbpedia.org/resource/Leonardo_da_Vinci>.
+08 <http://data.europeana.eu/item/04802/243FA8618938F4117025F17A8B813C5F9AA4D619> <http://purl.org/dc/terms/subject> <http://www.wikidata.org/entity/Q12418>.</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 <http://example.org/bob#me> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://xmlns.com/foaf/0.1/Person> <http://example.org/bob> .
+02 <http://example.org/bob#me> <http://xmlns.com/foaf/0.1/knows> <http://example.org/alice#me> <http://example.org/bob> .
+03 <http://example.org/bob#me> <http://schema.org/birthDate> "1990-07-04"^^<http://www.w3.org/2001/XMLSchema#date> <http://example.org/bob> .
+04 <http://example.org/bob#me> <http://xmlns.com/foaf/0.1/topic_interest> <http://www.wikidata.org/entity/Q12418> <http://example.org/bob> .
+05 <http://dbpedia.org/resource/Leonardo_da_Vinci> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://xmlns.com/foaf/0.1/Person> <https://www.wikidata.org/wiki/Special:EntityData/Q12418> .
+06 <http://dbpedia.org/resource/Leonardo_da_Vinci> <http://xmlns.com/foaf/0.1/name> "Leonardo da Vinci" <https://www.wikidata.org/wiki/Special:EntityData/Q12418> .
+07 <http://www.wikidata.org/entity/Q12418> <http://purl.org/dc/terms/creator> <http://dbpedia.org/resource/Leonardo_da_Vinci> <https://www.wikidata.org/wiki/Special:EntityData/Q12418> .
+08 <http://data.europeana.eu/item/04802/243FA8618938F4117025F17A8B813C5F9AA4D619> <http://purl.org/dc/terms/subject> <http://www.wikidata.org/entity/Q12418> <https://www.wikidata.org/wiki/Special:EntityData/Q12418> .
+09 <http://example.org/bob> <http://purl.org/dc/terms/publisher> <http://example.org> .
+10 <http://example.org/bob> <http://purl.org/dc/terms/rights> <http://creativecommons.org/licenses/by/3.0/> .</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 <?xml version="1.0" encoding="utf-8"?>
+02 <rdf:RDF
+03 xmlns:dcterms="http://purl.org/dc/terms/"
+04 xmlns:foaf="http://xmlns.com/foaf/0.1/"
+05 xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+06 xmlns:schema="http://schema.org/"
+07 xmlns:wd="http://www.wikidata.org/entity/"
+08 xmlns:xsd="http://www.w3.org/2001/XMLSchema#">
+09 <foaf:Person rdf:about="http://example.org/bob#me">
+10 <schema:birthDate rdf:datatype="http://www.w3.org/2001/XMLSchema#date">1990-07-04</schema:birthDate>
+11 <foaf:knows rdf:resource="http://example.org/alice#me"/>
+12 <foaf:topic_interest rdf:resource="http://www.wikidata.org/entity/Q12418"/>
+13 </foaf:Person>
+14 <foaf:Person rdf:about="http://dbpedia.org/resource/Leonardo_da_Vinci">
+15 <foaf:name>Leonardo da Vinci</foaf:name>
+16 </foaf:Person>
+17 <rdf:Description rdf:about="http://www.wikidata.org/entity/Q12418">
+18 <dcterms:creator rdf:resource="http://dbpedia.org/resource/Leonardo_da_Vinci"/>
+19 </rdf:Description>
+20 <rdf:Description rdf:about="http://data.europeana.eu/item/04802/243FA8618938F4117025F17A8B813C5F9AA4D619">
+21 <dcterms:subject rdf:resource="http://www.wikidata.org/entity/Q12418"/>
+22 </rdf:Description>
+23 </rdf:RDF></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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