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1708 lines
73 KiB
1708 lines
73 KiB
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
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"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<html xmlns="http://www.w3.org/1999/xhtml">
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<head>
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<meta content="HTML Tidy for Linux/x86 (vers 1st March 2003), see www.w3.org"
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name="generator" />
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<title>
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OWL Web Ontology Language Overview
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</title>
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<link rel="stylesheet" type="text/css"
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href="http://www.w3.org/StyleSheets/TR/W3C-CR" />
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<meta content="$Id: Overview.html,v 1.33 2003/08/16 12:02:47 sandro Exp $"
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name="RCSId" />
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<meta content="MSHTML 6.00.2800.1141" name="GENERATOR" />
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</head>
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<body lang="EN">
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<div class="head">
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<a href="http://www.w3.org/"><img height="48" alt="W3C"
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src="http://www.w3.org/Icons/w3c_home" width="72" /></a>
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<h1 id="mainTitle">
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OWL Web Ontology Language<br />
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Overview
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</h1>
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<h2>
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<a id="w3c-doctype" name="w3c-doctype"></a>
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W3C Candidate Recommendation 18 August 2003
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</h2>
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<dl>
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<dt>
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This version:
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</dt>
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<dd>
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<a href="http://www.w3.org/TR/2003/CR-owl-features-20030818/">
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http://www.w3.org/TR/2003/CR-owl-features-20030818/</a>
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</dd>
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<dt>
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Latest version:
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</dt>
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<dd>
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<a href="http://www.w3.org/TR/owl-features/">http://www.w3.org/TR/owl-features/</a>
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</dd>
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<dt>
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Previous version:
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</dt>
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<dd>
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<a href="http://www.w3.org/TR/2003/WD-owl-features-20030331/">
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http://www.w3.org/TR/2003/WD-owl-features-20030331/</a>
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</dd>
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<dt>
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Editors:
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</dt>
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<dd>
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Deborah L. McGuinness (Knowledge Systems Laboratory,
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Stanford University) <img align="middle"
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src="http://www.w3.org/2001/sw/WebOnt/guide-src/Email.Deborah.McGuinness.gif"
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alt="d l m at k s l dot stanford dot edu" /><br />
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</dd>
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<dd>
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Frank van Harmelen (Vrije Universiteit, Amsterdam)
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Frank.van.Harmelen@cs.vu.nl
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</dd>
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</dl>
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<p class="copyright"><a
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href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">
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Copyright</a> © 2003 <a href="http://www.w3.org/"><acronym
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title="World Wide Web
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Consortium">W3C</acronym></a><sup>®</sup> (<a
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|
href="http://www.lcs.mit.edu/"><acronym title="Massachusetts
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|
Institute of Technology">MIT</acronym></a>, <a
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|
href="http://www.ercim.org/"><acronym title="European Research
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|
Consortium for Informatics and Mathematics">ERCIM</acronym></a>,
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<a href="http://www.keio.ac.jp/">Keio</a>), All Rights
|
|
Reserved. W3C <a
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href="http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liability</a>,
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|
<a
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href="http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a>,
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|
<a
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|
href="http://www.w3.org/Consortium/Legal/copyright-documents">document
|
|
use</a> and <a
|
|
href="http://www.w3.org/Consortium/Legal/copyright-software">software
|
|
licensing</a> rules apply.</p>
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<hr title="Separator for header" />
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</div>
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<h2>
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<a id="abstract" name="abstract">Abstract</a>
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</h2>
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<p>
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The OWL Web Ontology Language is designed for use by
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applications that need to process the content of information
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instead of just presenting information to humans. OWL
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facilitates greater machine interpretability of Web content
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than that supported by XML, RDF, and RDF Schema (RDF-S) by
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providing additional vocabulary along with a formal
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semantics. OWL has three increasingly-expressive
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sublanguages: OWL Lite, OWL DL, and OWL Full.
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</p>
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<p>
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This document is written for readers who want a first
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impression of the capabilities of OWL. It provides an
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introduction to OWL by informally describing the features of
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each of the sublanguages of OWL. Some knowledge of
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<a href="#RDFSchema">RDF Schema</a> is
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useful for understanding this document, but not essential.
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After this document, interested readers may turn to the
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<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/">OWL
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Guide</a> for a more detailed descriptions and extensive
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examples on the features of OWL. The normative formal
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definition of OWL can be found in the
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<a href="http://www.w3.org/TR/2003/CR-owl-semantics-20030818/">
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OWL Semantics and Abstract Syntax</a>.
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</p>
|
|
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<h2><a id="status" name="status"></a>Status of this document</h2>
|
|
<div class="status">
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<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 W3C publications and the latest revision of this technical report can be found in the <a href="http://www.w3.org/TR/">W3C technical reports index</a> at http://www.w3.org/TR/.</em></p>
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<p><em>Publication as a Candidate Recommendation does not imply
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endorsement by the W3C Membership. This is a draft document and may be
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updated, replaced or obsoleted by other documents at any time. It is
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inappropriate to cite this document as other than "work in
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progress".</em></p>
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<p>This draft is one of <a href=
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"http://www.w3.org/TR/2003/CR-owl-features-20030818/#s1.1">six
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parts</a> of the <a
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href="http://www.w3.org/2003/06/Process-20030618/tr.html#cfi">Candidate
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Recommendation</a> (CR) for OWL, the Web Ontology Language. It has
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been developed by the <a href="http://www.w3.org/2001/sw/WebOnt/">Web
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Ontology Working Group</a> as part of the <a
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href="http://www.w3.org/2001/sw/">W3C Semantic Web Activity</a> (<a
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href="http://www.w3.org/2001/sw/Activity">Activity Statement</a>, <a
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href="http://www.w3.org/2001/sw/WebOnt/charter">Group Charter</a>) for
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publication on 18 August 2003. </p>
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<p>The design of OWL expressed in earlier versions of these documents
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has been widely reviewed and satisfies the Working Group's technical
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|
requirements. The Working Group has addressed <a
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|
href="http://lists.w3.org/Archives/Public/public-webont-comments/">
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|
all comments received</a>, making changes as necessary. Changes to
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this document since the <a
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href="http://www.w3.org/TR/2003/WD-owl-features-20030331/">Last Call
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Working Draft</a> are detailed in the <a href="#s8">change log</a>.
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</p>
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<p>The Working Group now hopes to gather experience from the growing
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number of <a href="http://www.w3.org/2001/sw/WebOnt/impls">OWL
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implementations</a> in order to increase confidence in the language
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and meet specific <a
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href="http://www.w3.org/2001/sw/WebOnt/impls#exit">exit criteria</a>.
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This CR period will extend until at least <strong><span
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class="commentsDue date">20 September 2003</span></strong>. After
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that date, when and if the exit criteria are met, the group intends to
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request <a
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href="http://www.w3.org/2003/06/Process-20030618/tr.html#RecsPR">
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|
Proposed Recommendation</a> status.</p>
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|
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<p>Please send reports of implementation experience to <a
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href="mailto:public-webont-comments@w3.org">public-webont-comments@w3.org</a>
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|
(<a
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|
href="http://lists.w3.org/Archives/Public/public-webont-comments/">archive</a>).
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|
Reports of any success or difficulty with the <a
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href="http://www.w3.org/TR/2003/CR-owl-test-20030818/">Test Cases</a>
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are encouraged, and reports received by 20 September 2003 will be
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|
particularly helpful. General discussion of related technology is
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|
welcome at <a href="mailto:www-rdf-logic@w3.org"
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|
shape="rect">www-rdf-logic@w3.org</a> (<a
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|
href="http://lists.w3.org/Archives/Public/www-rdf-logic/"
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|
shape="rect">archive</a>). </p>
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|
|
|
<p>Although OWL is essentially stable, later versions of these
|
|
documents are expected to contain minor improvements. The <a
|
|
href="http://www.w3.org/2002/03owlt/">test site</a> is likely to
|
|
include new, clarifying tests, even during this CR period.
|
|
Additionally, the design of OWL depends in part on the design of RDF,
|
|
and at this time the relevant RDF specifications are only Working
|
|
Drafts. It is therefore possible that unanticipated changes in RDF
|
|
may require changes to OWL.</p>
|
|
|
|
<p>The W3C maintains a list of <a
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|
href="http://www.w3.org/2001/sw/WebOnt/discl" rel="disclosure">any
|
|
patent disclosures related to this work</a>.</p>
|
|
|
|
<hr />
|
|
</div>
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|
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|
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<h2>
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|
<a id="contents" name="contents">Table of contents</a>
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</h2>
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<ol>
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<li>
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<a href="#s1">Introduction</a>
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|
<ol>
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<li>
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|
<a href="#s1.1">Document Roadmap</a>
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|
</li>
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<li>
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<a href="#s1.2">Why OWL?</a>
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</li>
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<li>
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<a href="#s1.3">The three sublanguages of OWL</a>
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</li>
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<li>
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<a href="#s1.4">The structure of this document</a>
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</li>
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</ol>
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</li>
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<li>
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<a href="#s2">Language Synopsis</a>
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<ol>
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<li>
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<a href="#s2.1">OWL Lite Synopsis</a>
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</li>
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<li>
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<a href="#s2.2">OWL DL and OWL Full Synopsis</a>
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|
</li>
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</ol>
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</li>
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<li>
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<a href="#s3">Language Description of OWL Lite</a>
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<ol>
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|
<li>
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<a href="#s3.1">OWL Lite RDF Schema Features</a>
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</li>
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<li>
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|
<a href="#s3.2">OWL Lite Equality and Inequality</a>
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|
</li>
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|
<li>
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|
<a href="#s3.3">OWL Lite Property Characteristics</a>
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|
</li>
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|
<li>
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|
<a href="#s3.4">OWL Lite Property Type Restrictions</a>
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|
</li>
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|
<li>
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|
<a href="#s3.5">OWL Lite Restricted Cardinality</a>
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|
</li>
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<li>
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<a href="#s3.6">OWL Lite Class Intersection</a>
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</li>
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<li>
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<a href="#s3.7">OWL Datatypes</a>
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</li>
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<li>
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<a href="#s3.8">OWL Lite Header Information</a>
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</li>
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<li>
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<a href="#s3.9">OWL Lite Annotation Properties</a>
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</li>
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</ol>
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</li>
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<li>
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<a href="#s4">Incremental Language Description of OWL DL
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and OWL Full</a>
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</li>
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<li>
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<a href="#s5">Summary</a>
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</li>
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<li style="LIST-STYLE-TYPE: none">
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<br />
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<a href="#s6">References</a>
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</li>
|
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<li style="LIST-STYLE-TYPE: none">
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<a href="#s7">Acknowledgements</a>
|
|
</li>
|
|
<li style="LIST-STYLE-TYPE: none">
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|
<a href="#s8">Change Log</a>
|
|
</li>
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</ol>
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<hr />
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<h2>
|
|
<a id="s1" name="s1"></a>1. Introduction
|
|
</h2>
|
|
<p>
|
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This document describes the OWL Web Ontology Language. OWL is
|
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intended to be used when the information contained in
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documents needs to be processed by applications, as opposed
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to situations where the content only needs to be presented to
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humans. OWL can be used to explicitly represent the meaning
|
|
of terms in vocabularies and the relationships between those
|
|
terms. This representation of terms and their
|
|
interrelationships is called an ontology. OWL has more
|
|
facilities for expressing meaning and semantics than XML,
|
|
RDF, and RDF-S, and thus OWL goes beyond these languages in
|
|
its ability to represent machine interpretable content on the
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Web. OWL is a revision of the
|
|
<a href="#DAMLReference">DAML+OIL
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web ontology language</a> incorporating lessons learned from
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the design and application of DAML+OIL.
|
|
</p>
|
|
<h3>
|
|
<a id="s1.1" name="s1.1"></a>1.1 Document Roadmap
|
|
</h3>
|
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<p>
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The OWL Language is described by a set of documents, each
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fulfilling a different purpose, and catering to a different
|
|
audience. The following provides a brief roadmap for
|
|
navigating through this set of documents:
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</p>
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<ul>
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<li>
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|
This
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|
<a href="http://www.w3.org/TR/2003/CR-owl-features-20030818/">
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OWL Overview</a> gives a simple introduction to OWL by
|
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providing a language feature listing with very brief
|
|
feature descriptions;
|
|
</li>
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<li>
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|
The
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/">OWL
|
|
Guide</a> demonstrates the use of the OWL language by
|
|
providing an extended example. It also provides a
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#OWLGlossary">glossary</a>
|
|
of the terminology used in these documents;
|
|
</li>
|
|
<li>
|
|
The
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-ref-20030818/">OWL
|
|
Reference</a> gives a systematic and compact (but still
|
|
informally stated) description of all the modelling
|
|
primitives of OWL;
|
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</li>
|
|
<li>
|
|
The
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-semantics-20030818/">
|
|
OWL Semantics and Abstract Syntax</a> document is the final
|
|
and formally stated normative definition of the language;
|
|
</li>
|
|
<li>
|
|
The
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-test-20030818/">OWL
|
|
Web Ontology Language Test Cases</a> document contains a
|
|
large set of test cases for the language;
|
|
</li>
|
|
<li>
|
|
The
|
|
<a href="http://www.w3.org/TR/2003/CR-webont-req-20030818/">
|
|
OWL Use Cases and Requirements</a> document contains a set
|
|
of use cases for a web ontology language and compiles a set
|
|
of requirements for OWL.
|
|
</li>
|
|
</ul>The suggested reading order of the first four documents is
|
|
as given since they have been listed in increasing degree of
|
|
technical content. The last two documents complete the
|
|
documentation set.
|
|
<h3>
|
|
<a id="s1.2" name="s1.2"></a>1.2 Why OWL?
|
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</h3>
|
|
<p>
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The Semantic Web is a vision for the future of the Web in
|
|
which information is given explicit meaning, making it easier
|
|
for machines to automatically process and integrate
|
|
information available on the Web. The Semantic Web will build
|
|
on XML's ability to define customized tagging schemes and
|
|
RDF's flexible approach to representing data. The first level
|
|
above RDF required for the Semantic Web is an ontology
|
|
language what can formally describe the meaning of
|
|
terminology used in Web documents. If machines are expected
|
|
to perform useful reasoning tasks on these documents, the
|
|
language must go beyond the basic semantics of RDF Schema.
|
|
The
|
|
<a href="http://www.w3.org/TR/2003/CR-webont-req-20030818/">OWL
|
|
Use Cases and Requirements Document</a> provides more
|
|
<a href="http://www.w3.org/TR/webont-req/#onto-def">details
|
|
on ontologies</a>, motivates the need for a Web Ontology
|
|
Language in terms of
|
|
<a href="http://www.w3.org/TR/webont-req/#section-use-cases">six
|
|
use cases</a>, and formulates
|
|
<a href="http://www.w3.org/TR/webont-req/#section-goals">design
|
|
goals</a>,
|
|
<a href="http://www.w3.org/TR/webont-req/#section-requirements">
|
|
requirements</a> and
|
|
<a href="http://www.w3.org/TR/webont-req/#section-objectives">
|
|
objectives</a> for OWL.
|
|
</p>
|
|
<p>
|
|
OWL has been designed to meet this need for a Web Ontology
|
|
Language. OWL is part of the growing stack of W3C
|
|
recommendations related to the Semantic Web.
|
|
</p>
|
|
<ul compact="compact">
|
|
<li>
|
|
<p>
|
|
<a href="http://www.w3.org/XML/">XML</a> provides a
|
|
surface syntax for structured documents, but imposes no
|
|
semantic constraints on the meaning of these documents.
|
|
</p>
|
|
</li>
|
|
<li>
|
|
<p>
|
|
<a href="http://www.w3.org/XML/Schema">XML Schema</a> is
|
|
a language for restricting the structure of XML
|
|
documents.
|
|
</p>
|
|
</li>
|
|
<li>
|
|
<p>
|
|
<a href="http://www.w3.org/TR/2002/WD-rdf-concepts-20021108/">
|
|
RDF</a> is a datamodel for objects ("resources") and
|
|
relations between them, provides a simple semantics for
|
|
this datamodel, and these datamodels can be represented
|
|
in an XML syntax.
|
|
</p>
|
|
</li>
|
|
<li>
|
|
<p>
|
|
<a href="http://www.w3.org/TR/2002/WD-rdf-schema-20021112/">
|
|
RDF Schema</a> is a vocabulary for describing properties
|
|
and classes of RDF resources, with a semantics for
|
|
generalization-hierarchies of such properties and
|
|
classes.
|
|
</p>
|
|
</li>
|
|
<li>
|
|
<p>
|
|
OWL adds more vocabulary for describing properties and
|
|
classes: among others, relations between classes (e.g.
|
|
disjointness), cardinality (e.g. "exactly one"),
|
|
equality, richer typing of properties, characteristics of
|
|
properties (e.g. symmetry), and enumerated classes.
|
|
</p>
|
|
</li>
|
|
</ul>
|
|
<h3>
|
|
<a id="s1.3" name="s1.3"></a>1.3 The three sublanguages of
|
|
OWL
|
|
</h3>
|
|
<p>
|
|
OWL provides three increasingly expressive sublanguages
|
|
designed for use by specific communities of implementers and
|
|
users.
|
|
</p>
|
|
<ul>
|
|
<li>
|
|
<p>
|
|
<a id="term_OWLLite" name="term_OWLLite"></a><em>OWL
|
|
Lite</em> supports those users primarily needing a
|
|
classification hierarchy and simple constraints. For
|
|
example, while it supports cardinality constraints, it
|
|
only permits cardinality values of 0 or 1. It should be
|
|
simpler to provide tool support for OWL Lite than its
|
|
more expressive relatives, and OWL Lite provides a quick
|
|
migration path for thesauri and other taxonomies. Owl
|
|
Lite also has a lower formal complexity than OWL DL, see
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-ref-20030818/#OWLLite">the
|
|
section on OWL Lite in the OWL Reference</a> for further
|
|
details.
|
|
</p>
|
|
</li>
|
|
<li>
|
|
<p>
|
|
<a id="term_OWLDL" name="term_OWLDL"></a><em>OWL DL</em>
|
|
supports those users who want the maximum expressiveness
|
|
while retaining computational completeness (all
|
|
conclusions are guaranteed to be computed) and
|
|
decidability (all computations will finish in finite
|
|
time). OWL DL includes all OWL language constructs, but
|
|
they can be used only under certain restrictions (for
|
|
example, while a class may be a subclass of many classes,
|
|
a class cannot be an instance of another class).
|
|
<!-- FvH: DELETED because too technical
|
|
with restrictions such as type separation (a class can not also be an individual or
|
|
property, a property can not also be an individual or class).
|
|
-->OWL DL is so named due
|
|
to its correspondence with
|
|
<a href="#DescriptionLogics"><em>description
|
|
logics</em></a>, a field of research that has studied the
|
|
logics that form the formal foundation of OWL.
|
|
</p>
|
|
</li>
|
|
<li>
|
|
<p>
|
|
<a id="term_OWLFull" name="term_OWLFull"></a><em>OWL
|
|
Full</em> is meant for users who want maximum
|
|
expressiveness and the syntactic freedom of RDF with no
|
|
computational guarantees. For example, in OWL Full a
|
|
class can be treated simultaneously as a collection of
|
|
individuals and as an individual in its own right. OWL
|
|
Full allows an ontology to augment the meaning of the
|
|
pre-defined (RDF or OWL) vocabulary. It is unlikely that
|
|
any reasoning software will be able to support complete
|
|
reasoning for every feature of OWL Full.
|
|
</p>
|
|
</li>
|
|
</ul>
|
|
<p>
|
|
Each of these sublanguages is an extension of its simpler
|
|
predecessor, both in what can be legally expressed and in
|
|
what can be validly concluded. The following set of relations
|
|
hold. Their inverses do not.
|
|
</p>
|
|
<ul>
|
|
<li>
|
|
Every legal OWL Lite ontology is a legal OWL DL ontology.
|
|
</li>
|
|
<li>
|
|
Every legal OWL DL ontology is a legal OWL Full ontology.
|
|
</li>
|
|
<li>
|
|
Every valid OWL Lite conclusion is a valid OWL DL
|
|
conclusion.
|
|
</li>
|
|
<li>
|
|
Every valid OWL DL conclusion is a valid OWL Full
|
|
conclusion.
|
|
</li>
|
|
</ul>
|
|
<p>
|
|
Ontology developers adopting OWL should consider which
|
|
sublanguage best suits their needs. The choice between OWL
|
|
Lite and OWL DL depends on the extent to which users require
|
|
the more-expressive constructs provided by OWL DL and OWL
|
|
Full. The choice between OWL DL and OWL Full mainly depends
|
|
on the extent to which users require the meta-modeling
|
|
facilities of RDF Schema (e.g. defining classes of classes,
|
|
or attaching properties to classes). When using OWL Full as
|
|
compared to OWL DL, reasoning support is less predictable
|
|
since complete OWL Full implementations do not currently
|
|
exist.
|
|
</p>OWL Full can be viewed as an extension of RDF, while OWL
|
|
Lite and OWL DL can be viewed as extensions of a restricted
|
|
view of RDF. Every OWL (Lite, DL, Full) document is an RDF
|
|
document, and every RDF document is an OWL Full document, but
|
|
only some RDF documents will be a legal OWL Lite or OWL DL
|
|
document. Because of this, some care has to be taken when a
|
|
user wants to migrate an RDF document to OWL. When the
|
|
expressiveness of OWL DL or OWL Lite is deemed appropriate,
|
|
some precautions have to be taken to ensure that the original
|
|
RDF document complies with the additional constraints emposed
|
|
by OWL DL and OWL Lite. Among others, every URI that is used as
|
|
a class name must be explicitly asserted to be of type
|
|
owl:Class (and simililarly for properties), every individual
|
|
must be asserted to belong to at least one class (even if only
|
|
owl:Thing), the URI's used for classes, properties and
|
|
individuals must be mutually disjoint. The details of these and
|
|
other constraints on OWL DL and OWL Lite are explained in
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-ref-20030818/#app-DLinRDF">appendix E
|
|
of the OWL Reference</a>.
|
|
<h3>
|
|
<a id="s1.4" name="s1.4"></a>1.4 The structure of this
|
|
document
|
|
</h3>
|
|
<p>
|
|
This document first describes the features from OWL Lite,
|
|
followed by a description from the features that are added in
|
|
OWL DL and OWL Full (OWL DL and OWL Full contain the same
|
|
features, but OWL Full is more liberal about how these
|
|
features can be combined).
|
|
</p>
|
|
<h2>
|
|
<a id="s2" name="s2"></a>2. Language Synopsis
|
|
</h2>This section provides a quick index to all the language
|
|
features for OWL Lite, OWL DL, and OWL Full.
|
|
<p>
|
|
In this document, italicized terms are terms in OWL. Prefixes
|
|
of rdf: or rdfs: are used when terms are already present in
|
|
RDF or RDF Schema. Otherwise terms are introduced by OWL.
|
|
Thus, the term <i>rdfs:subPropertyOf</i> indicates that
|
|
subPropertyOf is already in the rdfs vocabulary (technically
|
|
: the rdfs namespace). Also, the term <i>Class</i> is more
|
|
precisely stated as <i>owl:Class</i> and is a term introduced
|
|
by OWL.
|
|
</p>
|
|
<h3>
|
|
<a id="s2.1" name="s2.1"></a>2.1 OWL Lite Synopsis
|
|
</h3>
|
|
<p>
|
|
The list of OWL Lite language constructs is given below.
|
|
</p>
|
|
<table width="100%" cellspacing="30">
|
|
<tr>
|
|
<td class="index" valign="top">
|
|
<b>RDF Schema Features:</b>
|
|
<ul>
|
|
<li>
|
|
<i><a href="#Class">Class</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#property">rdf:Property</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#subClassOf">rdfs:subClassOf</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#subPropertyOf">rdfs:subPropertyOf</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#domain">rdfs:domain</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#range">rdfs:range</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#Individual">Individual</a></i>
|
|
</li>
|
|
</ul>
|
|
</td>
|
|
<td class="index" valign="top">
|
|
<b>(In)Equality:</b>
|
|
<ul>
|
|
<li>
|
|
<i><a href="#equivalentClass">equivalentClass</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#equivalentProperty">equivalentProperty</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#sameAs">sameAs</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#differentFrom">differentFrom</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#allDifferent">allDifferent</a></i>
|
|
</li>
|
|
</ul>
|
|
</td>
|
|
<td class="index" valign="top">
|
|
<b>Property Characteristics:</b>
|
|
<ul>
|
|
<li>
|
|
<i><a href="#inverseOf">inverseOf</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#TransitiveProperty">TransitiveProperty</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#SymmetricProperty">SymmetricProperty</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#FunctionalProperty">FunctionalProperty</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#InverseFunctionalProperty">InverseFunctionalProperty</a></i>
|
|
</li>
|
|
</ul>
|
|
</td>
|
|
</tr>
|
|
<tr>
|
|
<td class="index" valign="top">
|
|
<b>Property Type Restrictions:</b>
|
|
<ul>
|
|
<li>
|
|
<i><a href="#allValuesFrom">allValuesFrom</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#someValuesFrom">someValuesFrom</a></i>
|
|
</li>
|
|
</ul>
|
|
</td>
|
|
<td class="index" valign="top">
|
|
<b>Restricted Cardinality:</b>
|
|
<ul>
|
|
<li>
|
|
<i><a href="#minCardinality">minCardinality</a></i>
|
|
(only 0 or 1)
|
|
</li>
|
|
<li>
|
|
<i><a href="#maxCardinality">maxCardinality</a></i>
|
|
(only 0 or 1)
|
|
</li>
|
|
<li>
|
|
<i><a href="#Cardinality">cardinality</a></i> (only 0
|
|
or 1)
|
|
</li>
|
|
</ul>
|
|
</td>
|
|
<td class="index" valign="top">
|
|
<b>Header Information:</b>
|
|
<ul>
|
|
<li>
|
|
<i><a href="#s3.8">ontology</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#s3.8">imports</a></i>
|
|
</li>
|
|
</ul>
|
|
</td>
|
|
</tr>
|
|
<tr>
|
|
<td class="index" valign="top">
|
|
<b>Class Intersection:</b>
|
|
<ul>
|
|
<li>
|
|
<i><a href="#intersectionOf">intersectionOf</a></i>
|
|
</li>
|
|
</ul>
|
|
</td>
|
|
<td class="index" valign="top" rowspan="2">
|
|
<b>Versioning:</b>
|
|
<ul>
|
|
<li>
|
|
<i><a href="#s3.10">versionInfo</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#s3.10">priorVersion</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#s3.10">backwardCompatibleWith</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#s3.10">inCompatibleWith</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#s3.10">DeprecatedClass</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#s3.10">DeprecatedProperty</a></i>
|
|
</li>
|
|
</ul>
|
|
</td>
|
|
<td class="index" valign="top" rowspan="2">
|
|
<b>Annotation Properties:</b>
|
|
<ul>
|
|
<li>
|
|
<i><a href="#s3.9">rdfs:label</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#s3.9">rdfs:comment</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#s3.9">rdfs:seeAlso</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#s3.9">rdfs:isDefinedBy</a></i>
|
|
</li>
|
|
</ul>
|
|
</td>
|
|
</tr>
|
|
<tr>
|
|
<td class="index" valign="top">
|
|
<b>Datatypes</b>
|
|
<ul>
|
|
<li>
|
|
<i><a href="#s3.7">DatatypeProperty</a></i>
|
|
</li>
|
|
</ul>
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
<h3>
|
|
<a id="s2.2" name="s2.2"></a>2.2 OWL DL and Full Synopsis
|
|
</h3>
|
|
<p>
|
|
The list of OWL DL and OWL Full language constructs that are
|
|
in addition to those of OWL Lite is given below.
|
|
</p>
|
|
<table cellspacing="30" width="100%">
|
|
<colgroup span="4" width="1"></colgroup>
|
|
<tbody>
|
|
<tr>
|
|
<td class="index" valign="top">
|
|
<b>Class Axioms:</b>
|
|
<ul>
|
|
<li>
|
|
<i><a href="#oneOf">oneOf, dataRange</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#disjointWith">disjointWith</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#complexClassFull">equivalentClass</a></i><br />
|
|
|
|
(applied to class expressions)
|
|
</li>
|
|
<li>
|
|
<i><a href="#complexClassFull">rdfs:subClassOf</a></i><br />
|
|
|
|
(applied to class expressions)
|
|
</li>
|
|
</ul>
|
|
</td>
|
|
<td class="index" valign="top">
|
|
<b>Boolean Combinations of Class Expressions:</b>
|
|
<ul>
|
|
<li>
|
|
<i><a href="#booleanFull">unionOf</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#booleanFull">intersectionOf</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#booleanFull">complementOf</a></i>
|
|
</li>
|
|
</ul>
|
|
</td>
|
|
</tr>
|
|
</tbody>
|
|
<tbody>
|
|
<tr>
|
|
<td class="index" valign="top">
|
|
<b>Arbitrary Cardinality:</b>
|
|
<ul>
|
|
<li>
|
|
<i><a href="#cardinalityFull">minCardinality</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#cardinalityFull">maxCardinality</a></i>
|
|
</li>
|
|
<li>
|
|
<i><a href="#cardinalityFull">cardinality</a></i>
|
|
</li>
|
|
</ul>
|
|
</td>
|
|
<td class="index" valign="top">
|
|
<b>Filler Information:</b>
|
|
<ul>
|
|
<li>
|
|
<i><a href="#hasValue">hasValue</a></i>
|
|
</li>
|
|
</ul>
|
|
</td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
<h2>
|
|
<a id="s3" name="s3"></a>3. Language Description of OWL Lite
|
|
</h2>
|
|
<p>
|
|
This section provides an informal description of the OWL Lite
|
|
language features. We do not discuss the specific syntax of
|
|
these features (see the
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-ref-20030818/">OWL
|
|
Reference</a> for definitions). Each language feature is
|
|
hyperlinked to the appropriate place in the
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/">OWL
|
|
Guide</a> for more examples and guidance on usage.
|
|
</p>
|
|
<p>
|
|
OWL Lite uses only some of the OWL language features and has
|
|
more limitations on the use of the features than OWL DL or
|
|
OWL Full. For example, in OWL Lite classes can only be
|
|
defined in terms of named superclasses (superclasses cannot
|
|
be arbitrary expressions), and only certain kinds of class
|
|
restrictions can be used. Equivalence between classes and
|
|
subclass relationships between classes are also only allowed
|
|
between named classes, and not between arbitrary class
|
|
expressions. Similarly, restrictions in OWL Lite use only
|
|
named classes. OWL Lite also has a limited notion of
|
|
cardinality - the only cardinalities allowed to be explicitly
|
|
stated are 0 or 1.
|
|
</p>
|
|
<h3>
|
|
<a id="s3.1" name="s3.1"></a>3.1 OWL Lite RDF Schema Features
|
|
</h3><!-- FvH: now obsolete because of term glossary in Guide
|
|
This document uses the term "individual"
|
|
to refer
|
|
to objects that belong to classes (e.g., the individual Deborah belongs to the
|
|
class Person) as well as to objects that are datatypes (e.g., the individual 4
|
|
is an integer).
|
|
-->
|
|
<p>
|
|
The following OWL Lite features related to RDF Schema are
|
|
included.
|
|
</p>
|
|
<ul>
|
|
<li>
|
|
<b><i><a id="Class" name="Class"></a>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#owl_Class">Class</a></i></b>:
|
|
A class defines a group of individuals that belong together
|
|
because they share some properties. For example, Deborah
|
|
and Frank are both members of the class Person. Classes can
|
|
be organized in a specialization hierarchy using
|
|
<a href="#subClassOf"><i>subClassOf</i></a>. There is a
|
|
built-in most general class named Thing that is the class
|
|
of all individuals and a superclass of all OWL classes.
|
|
There is also a built-in most specific class named Nothing
|
|
that is the class that has no instances and a subclass of
|
|
all OWL classes.
|
|
</li>
|
|
<li>
|
|
<b><i><a id="subClassOf" name="subClassOf"></a>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#rdfs_subClassOf">rdfs:subClassOf</a></i></b>:
|
|
Class hierarchies may be created by making one or more
|
|
statements that a class is a subclass of another class. For
|
|
example, the class Person could be stated to be a subclass
|
|
of the class Mammal. From this a reasoner can deduce that
|
|
if an individual is a Person, then it is a Mammal.
|
|
</li>
|
|
<li>
|
|
<b><i><a id="property" name="property"></a>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#DefiningProperties">rdfs:Property</a></i></b>:
|
|
Properties can be used to state relationships between
|
|
individuals or from individuals to data values. Examples of
|
|
properties include hasChild, hasRelative, hasSibling, and
|
|
hasAge. The first three can be used to relate an instance
|
|
of a class Person to another instance of the class Person
|
|
(and are thus ObjectProperties), and the last (hasAge) can
|
|
be used to relate an instance of the class Person to an
|
|
instance of the datatype Integer (and is thus a Datatype
|
|
property).
|
|
</li>
|
|
<li>
|
|
<b><i><a id="subPropertyOf" name="subPropertyOf"></a>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#rdfs_subPropertyOf">
|
|
rdfs:subPropertyOf</a></i></b>: Property hierarchies may be
|
|
created by making one or more statements that a property is
|
|
a subproperty of one or more other properties. For example,
|
|
hasSibling may be stated to be a subproperty of
|
|
hasRelative. From this a reasoner can deduce that if an
|
|
individual is related to another by the hasSibling
|
|
property, then it is also related to the other by the
|
|
hasRelative property.
|
|
</li>
|
|
<li>
|
|
<b><i><a id="domain" name="domain"></a>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#term_domain">rdfs:domain</a></i></b>:
|
|
A domain of a property limits the individuals to which the
|
|
property can be applied. If a property relates individual
|
|
to another individual, and the property has a class as one
|
|
of its domains, then the individual must belong to the
|
|
class. For example, the property hasChild may be stated to
|
|
have the domain of Mammal. From this a reasoner can deduce
|
|
that if Frank hasChild Anna, then Frank must be a Mammal.
|
|
Note that <i>rdfs:domain</i> is called a global restriction
|
|
since the restriction is stated on the property and not
|
|
just on the property when it is associated with a
|
|
particular class. See the discussion below on local
|
|
restrictions for more information.
|
|
</li>
|
|
<li>
|
|
<b><i><a id="range" name="range"></a>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#term_range">rdfs:range</a></i></b>:
|
|
The range of a property limits the individuals that the
|
|
property may have as its value. If a property relates an
|
|
individual to another individual, and the property has a
|
|
class as its range, then the other indivual must belong to
|
|
the range class. For example, the property hasChild may be
|
|
stated to have the range of Mammal. From this a reasoner
|
|
can deduce that if Louise is related to Deborah by the
|
|
hasChild property, i.e., Deborah is the child of Louise,
|
|
then Deborah is a Mammal. Range is also a global
|
|
restriction as is domain above. Again, see the discussion
|
|
below on local restrictions (e.g.
|
|
<a href="#allValuesFrom">AllValuesFrom</a>) for more
|
|
information.
|
|
</li>
|
|
<li>
|
|
<b><i><a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#term_individual">
|
|
Individual</a><a id="Individual"
|
|
name="Individual"></a></i></b> : Individuals are instances
|
|
of classes, and properties may be used to relate one
|
|
individual to another. For example, an individual named
|
|
Deborah may be described as an instance of the class Person
|
|
and the property hasEmployer may be used to relate the
|
|
individual Deborah to the individual StanfordUniversity.
|
|
</li>
|
|
</ul>
|
|
<h3>
|
|
<a id="s3.2" name="s3.2"></a>3.2 OWL Lite Equality and
|
|
Inequality
|
|
</h3>The following OWL Lite features are related to equality or
|
|
inequality.
|
|
<ul>
|
|
<li>
|
|
<b><i><a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#owl_equivalentClass">
|
|
equivalentClass</a><a id="equivalentClass"
|
|
name="equivalentClass"></a></i></b> : Two classes may be
|
|
stated to be equivalent. Equivalent classes have the same
|
|
instances. Equality can be used to create synonymous
|
|
classes. For example, Car can be stated to be
|
|
<i>equivalentClass</i> to Automobile. From this a reasoner
|
|
can deduce that any individual that is an instance of Car
|
|
is also an instance of Automobile and vice versa.
|
|
</li>
|
|
<li>
|
|
<b><i><a id="equivalentProperty"
|
|
name="equivalentProperty"></a>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#owl_equivalentProperty">
|
|
equivalentProperty</a></i></b>: Two properties may be
|
|
stated to be equivalent. Equivalent properties relate one
|
|
individual to the same set of other individuals. Equality
|
|
may be used to create synonymous properties. For example,
|
|
hasLeader may be stated to be the <i>equivalentProperty</i>
|
|
to hasHead. From this a reasoner can deduce that if X is
|
|
related to Y by the property hasLeader, X is also related
|
|
to Y by the property hasHead and vice versa. A reasoner can
|
|
also deduce that hasLeader is a subproperty of hasHead and
|
|
hasHead is a subProperty of hasLeader.
|
|
</li>
|
|
<li>
|
|
<a id="sameAs" name="sameAs"></a>
|
|
<b><i><a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#owl_sameAs">sameAs</a></i></b>:
|
|
Two individuals may be stated to be the same. These
|
|
constructs may be used to create a number of different
|
|
names that refer to the same individual. For example, the
|
|
individual Deborah may be stated to be the same individual
|
|
as DeborahMcGuinness.
|
|
</li>
|
|
<li>
|
|
<b><i><a id="differentFrom" name="differentFrom"></a>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#differentFrom">differentFrom</a></i></b>:
|
|
An individual may be stated to be different from other
|
|
individuals. For example, the individual Frank may be
|
|
stated to be different from the individuals Deborah and
|
|
Jim. Thus, if the individuals Frank and Deborah are both
|
|
values for a property that is stated to be functional (thus
|
|
the property has at most one value), then there is a
|
|
contradiction. Explicitly stating that individuals are
|
|
different can be important in when using languages such as
|
|
OWL (and RDF) that do not assume that individuals have one
|
|
and only one name. For example, with no additional
|
|
information, a reasoner will not deduce that Frank and
|
|
Deborah refer to distinct individuals.
|
|
</li>
|
|
<li>
|
|
<b><i><a id="allDifferent" name="allDifferent"></a>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#owl_AllDifferent">allDifferent</a></i></b>:
|
|
A number of individuals may be stated to be mutually
|
|
distinct in one allDifferent statement. For example, Frank,
|
|
Deborah, and Jim could be stated to be mutually distinct
|
|
using the allDifferent construct. Unlike the differentFrom
|
|
statement above, this would also enforce that Jim and
|
|
Deborah are distinct (not just that Frank is distinct from
|
|
Deborah and Frank is distinct from Jim). The allDifferent
|
|
construct is particularly useful when there are sets of
|
|
distinct objects and when modelers are interested in
|
|
enforcing the unique names assumption within those sets of
|
|
objects.
|
|
</li>
|
|
</ul>
|
|
<h3>
|
|
<a id="s3.3" name="s3.3"></a>3.3 OWL Lite Property
|
|
Characteristics
|
|
</h3>There are special identifiers in OWL Lite that are used to
|
|
provide information concerning properties and their values.
|
|
<ul>
|
|
<li>
|
|
<b><i><a id="inverseOf" name="inverseOf"></a>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#owl_inverseOf">inverseOf</a></i></b>:
|
|
One property may be stated to be the inverse of another
|
|
property. If the property P1 is stated to be the inverse of
|
|
the property P2, then if X is related to Y by the P2
|
|
property, then Y is related to X by the P1 property. For
|
|
example, if hasChild is the inverse of hasParent and
|
|
Deborah hasParent Louise, then a reasoner can deduce that
|
|
Louise hasChild Deborah.
|
|
</li>
|
|
<li>
|
|
<b><i><a id="TransitiveProperty"
|
|
name="TransitiveProperty"></a>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#owl_TransitiveProperty">
|
|
TransitiveProperty</a></i></b>: Properties may be stated to
|
|
be transitive. If a property is transitive, then if the
|
|
pair (x,y) is an instance of the transitive property P, and
|
|
the pair (y,z) is an instance of P, then the pair (x,z) is
|
|
also an instance of P. For example, if ancestor is stated
|
|
to be transitive, and if Sara is an ancestor of Louise
|
|
(i.e., (Sara,Louise) is an instance of the property
|
|
ancestor) and Louise is an ancestor of Deborah (i.e.,
|
|
(Louise,Deborah) is an instance of the property ancestor),
|
|
then a reasoner can deduce that Sara is an ancestor of
|
|
Deborah (i.e., (Sara,Deborah) is an instance of the
|
|
property ancestor).<br />
|
|
OWL Lite (and OWL DL) impose the side condition that
|
|
transitive properties (and their superproperties) cannot
|
|
have a maxCardinality 1 restriction. Without this
|
|
side-condition, OWL Lite and OWL DL would become
|
|
undecidable languages. See the property axiom section of
|
|
the <a href="http://www.w3.org/TR/owl-semantics/">OWL
|
|
Semantics and Abstract Syntax</a> document for more
|
|
information.
|
|
</li>
|
|
<li>
|
|
<b><i><a id="SymmetricProperty"
|
|
name="SymmetricProperty"></a>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#owl_SymmetricProperty">
|
|
SymmetricProperty</a></i></b>: Properties may be stated to
|
|
be symmetric. If a property is symmetric, then if the pair
|
|
(x,y) is an instance of the symmetric property P, then the
|
|
pair (y,x) is also an instance of P. For example, friend
|
|
may be stated to be a symmetric property. Then a reasoner
|
|
that is given that Frank is a friend of Deborah can deduce
|
|
that Deborah is a friend of Frank.
|
|
</li>
|
|
<li>
|
|
<b><i><a id="FunctionalProperty"
|
|
name="FunctionalProperty"></a>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#owl_FunctionalProperty">
|
|
FunctionalProperty</a></i></b> : Properties may be stated
|
|
to have a unique value. If a property is a
|
|
FunctionalProperty, then it has no more than one value for
|
|
each individual (it may have no values for an individual).
|
|
This characteristic has been referred to as having a unique
|
|
property. FunctionalProperty is shorthand for stating that
|
|
the property's minimum cardinality is zero and its maximum
|
|
cardinality is 1. For example, hasPrimaryEmployer may be
|
|
stated to be a FunctionalProperty. From this a reasoner may
|
|
deduce that no individual may have more than one primary
|
|
employer. This does not imply that every Person must have
|
|
at least one primary employer however.
|
|
</li>
|
|
<li>
|
|
<b><i><a id="InverseFunctionalProperty"
|
|
name="InverseFunctionalProperty"></a>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#owl_InverseFunctionalProperty">
|
|
InverseFunctionalProperty</a></i></b>: Properties may be
|
|
stated to be inverse functional. If a property is inverse
|
|
functional then the inverse of the property is functional.
|
|
Thus the inverse of the property has at most one value for
|
|
each individual. This characteristic has also been referred
|
|
to as an unambiguous property. For example,
|
|
hasUSSocialSecurityNumber (a unique identifier for United
|
|
States residents) may be stated to be inverse functional
|
|
(or unambiguous). The inverse of this property (which may
|
|
be referred to as isTheSocialSecurityNumberFor) has at most
|
|
one value for any individual in the class of social
|
|
security numbers. Thus any one person's social security
|
|
number is the only value for their
|
|
isTheSocialSecurityNumberfor property. From this a reasoner
|
|
can deduce that no two different individual instances of
|
|
Person have the identical US Social Security Number. Also,
|
|
a reasoner can deduce that if two instances of Person have
|
|
the same social security number, then those two instances
|
|
refer to the same individual.
|
|
</li>
|
|
</ul>
|
|
<h3>
|
|
<a id="s3.4" name="s3.4"></a>3.4 OWL Lite Property Type
|
|
Restriction
|
|
</h3>OWL Lite allows restrictions to be placed on how
|
|
properties can be used by instances of a class. The following
|
|
two restrictions limit which values can be used while the next
|
|
section's restrictions limit how many values can be used.
|
|
<ul>
|
|
<li>
|
|
<b><i><a id="allValuesFrom" name="allValuesFrom"></a>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#owl_allValuesFrom">
|
|
allValuesFrom</a></i></b>: The restriction allValuesFrom is
|
|
stated on a property with respect to a class. It means that
|
|
this property on this particular class has a local range
|
|
restriction associated with it. Thus if an instance of the
|
|
class is related by the property to a second individual,
|
|
then the second individual can be inferred to be an
|
|
instance of the local range restriction class. For example,
|
|
the class Person may have a property called hasDaughter
|
|
restricted to have allValuesFrom the class Woman. This
|
|
means that if an individual person Louise is related by the
|
|
property hasDaughter to the individual Deborah, then from
|
|
this a reasoner can deduce that Deborah is an instance of
|
|
the class Woman. This restriction allows the property
|
|
hasDaughter to be used with other classes, such as the
|
|
class Cat, and have an appropriate value restriction
|
|
associated with the use of the property on that class. In
|
|
this case, hasDaughter would have the local range
|
|
restriction of Cat when associated with the class Cat and
|
|
would have the local range restriction Person when
|
|
associated with the class Person. Note that a reasoner can
|
|
not deduce from an allValuesFrom restriction alone that
|
|
there actually is at least one value for the property.
|
|
</li>
|
|
<li>
|
|
<b><i><a id="someValuesFrom" name="someValuesFrom"></a>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#owl_someValuesFrom">
|
|
someValuesFrom</a></i></b>: The restriction
|
|
<i>someValuesFrom</i> is stated on a property with respect
|
|
to a class. A particular class may have a restriction on a
|
|
property that at least one value for that property is of a
|
|
certain type. For example, the class SemanticWebPaper may
|
|
have a <i>someValuesFrom</i> restriction on the hasKeyword
|
|
property that states that <u>some</u> value for the
|
|
hasKeyword property should be an instance of the class
|
|
SemanticWebTopic. This allows for the option of having
|
|
multiple keywords and as long as one or more is an instance
|
|
of the class SemanticWebTopic, then the paper would be
|
|
consistent with the <i>someValuesFrom</i> restriction.
|
|
Unlike <i>allValuesFrom</i>, <i>someValuesFrom</i> does not
|
|
restrict all the values of the property to be instances of
|
|
the same class. If myPaper is an instance of the
|
|
SemanticWebPaper class, then myPaper is related by the
|
|
<i>hasKeyword</i> property to at least one instance of the
|
|
SemanticWebTopic class. Note that a reasoner can not deduce
|
|
(as it could with <i>allValuesFrom</i> restrictions) that
|
|
<u>all</u> values of hasKeyword are instances of the
|
|
SemanticWebTopic class
|
|
</li>
|
|
</ul>
|
|
<h3>
|
|
<a id="s3.5" name="s3.5"></a>3.5 OWL Lite Restricted
|
|
Cardinality
|
|
</h3>
|
|
<p>
|
|
OWL Lite includes a limited form of cardinality restrictions.
|
|
OWL (and OWL Lite) cardinality restrictions are referred to
|
|
as local restrictions, since they are stated on properties
|
|
with respect to a particular class. That is, the restrictions
|
|
constrain the cardinality of that property on instances of
|
|
that class. OWL Lite cardinality restrictions are limited
|
|
because they only allow statements concerning cardinalities
|
|
of value 0 or 1 (they do not allow arbitrary values for
|
|
cardinality, as is the case in OWL DL and OWL Full).
|
|
</p>
|
|
<ul>
|
|
<li>
|
|
<b><i><a id="minCardinality" name="minCardinality"></a>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#owl_minCardinality">
|
|
minCardinality</a></i></b>: Cardinality is stated on a
|
|
property with respect to a particular class. If a
|
|
<i>minCardinality</i> of 1 is stated on a property with
|
|
respect to a class, then any instance of that class will be
|
|
related to at least one individual by that property. This
|
|
restriction is another way of saying that the property is
|
|
<u>required</u> to have a value for all instances of the
|
|
class. For example, the class Person would not have any
|
|
minimum cardinality restrictions stated on a hasOffspring
|
|
property since not all persons have offspring. The class
|
|
Parent, however would have a minimum cardinality of 1 on
|
|
the hasOffspring property. If a reasoner knows that Louise
|
|
is a Person, then nothing can be deduced about a minimum
|
|
cardinality for her hasOffspring property. Once it is
|
|
discovered that Louise is an instance of Parent, then a
|
|
reasoner can deduce that Louise is related to at least one
|
|
individual by the hasOffspring property. From this
|
|
information alone, a reasoner can not deduce any maximum
|
|
number of offspring for individual instances of the class
|
|
parent. In OWL Lite the only minimum cardinalities allowed
|
|
are 0 or 1. A minimum cardinality of zero on a property
|
|
just states (in the absence of any more specific
|
|
information) that the property is optional with respect to
|
|
a class. For example, the property hasOffspring may have a
|
|
minimum cardinality of zero on the class Person (while it
|
|
is stated to have the more specific information of minimum
|
|
cardinality of one on the class Parent).
|
|
</li>
|
|
<li>
|
|
<b><i><a id="maxCardinality" name="maxCardinality"></a>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#owl_maxCardinality">
|
|
maxCardinality</a></i></b>: Cardinality is stated on a
|
|
property with respect to a particular class. If a
|
|
<i>maxCardinality</i> of 1 is stated on a property with
|
|
respect to a class, then any instance of that class will be
|
|
related to at most one individual by that property. A
|
|
maxCardinality 1 restriction is sometimes called a
|
|
functional or unique property. For example, the property
|
|
hasRegisteredVotingState on the class UnitedStatesCitizens
|
|
may have a maximum cardinality of one (because people are
|
|
only allowed to vote in only one state). From this a
|
|
reasoner can deduce that individual instances of the class
|
|
USCitizens may not be related to two or more distinct
|
|
individuals through the hasRegisteredVotingState property.
|
|
From a maximum cardinality one restriction alone, a
|
|
reasoner can not deduce a minimum cardinality of 1. It may
|
|
be useful to state that certain classes have no values for
|
|
a particular property. For example, instances of the class
|
|
UnmarriedPerson should not be related to <u>any</u>
|
|
individuals by the property hasSpouse. This situation is
|
|
represented by a maximum cardinality of zero on the
|
|
hasSpouse property on the class UnmarriedPerson.
|
|
</li>
|
|
<li>
|
|
<b><i><a id="Cardinality" name="Cardinality"></a>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#owl_cardinality">cardinality</a></i></b>:
|
|
Cardinality is provided as a convenience when it is useful
|
|
to state that a property on a class has both
|
|
<i>minCardinality</i> 0 and <i>maxCardinality</i> 0 or both
|
|
<i>minCardinality</i> 1 and <i>maxCardinality</i> 1. For
|
|
example, the class Person has exactly one value for the
|
|
property hasBirthMother. From this a reasoner can deduce
|
|
that no two distinct individual instances of the class
|
|
Mother may be values for the hasBirthMother property of the
|
|
same person.
|
|
</li>
|
|
</ul>Alternate namings for these restricted forms of
|
|
cardinality were discussed. Current recommendations are to
|
|
include any such names in a front end system. More on this
|
|
topic is available on the publically available webont mail
|
|
archives with the most relevant message at
|
|
<a href="http://lists.w3.org/Archives/Public/www-webont-wg/2002Oct/0063.html">
|
|
http://lists.w3.org/Archives/Public/www-webont-wg/2002Oct/0063.html</a>.
|
|
|
|
<h3>
|
|
<a id="s3.6" name="s3.6"></a>3.6 OWL Lite Class Intersection
|
|
</h3>OWL Lite contains an intersection constructor but limits
|
|
its usage. <!--(OWL full does not place limitations
|
|
on the use of boolean constructors such as intersection.
|
|
-->
|
|
|
|
<ul>
|
|
<li>
|
|
<b><i><a id="intersectionOf" name="intersectionOf"></a>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#owl_intersectionOf">
|
|
intersectionOf</a></i></b>: OWL Lite allows intersections
|
|
of named classes and restrictions. For example, the class
|
|
EmployedPerson can be described as the
|
|
<i>intersectionOf</i> Person and EmployedThings (which
|
|
could be defined as things that have a minimum cardinality
|
|
of 1 on the hasEmployer property). From this a reasoner may
|
|
deduce that any particular EmployedPerson has at least one
|
|
employer.
|
|
<!-- OWL Lite requires <i>intersectionOf</i> to take named
|
|
classes thus it would not be allowed in OWL Lite to
|
|
describe EmployedPerson as the intersection of Person
|
|
and the unnamed the class of things that have at
|
|
least one employer and is simultaneously an instance
|
|
of the class Person.
|
|
The ability to use unnamed classes is introduced in
|
|
OWL DL and OWL Full.
|
|
-->
|
|
</li>
|
|
</ul>
|
|
<h3>
|
|
<a id="s3.7" name="s3.7"></a>3.7 Datatypes
|
|
</h3>
|
|
<p>
|
|
OWL uses the RDF mechanisms for data values.
|
|
<!-- dlm: removed with suggestion from pfps. too much detail.
|
|
datatyping scheme, which provides a mechanism for referring to pointer
|
|
href="http://www.daml.org/2002/06/webont/owl-ref-proposed#ref-xml-schema2">XML
|
|
Schema datatypes</A>. Such XML Schema datatypes are identified by a URI, and
|
|
each time an instance of such a datatype occurs, it must have an RDF attribute
|
|
rdf:datatype whose value should be the URI reference of the XML Schema datatype.
|
|
-->See the
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/">OWL Guide</a> for a
|
|
more detailed description.
|
|
</p>
|
|
<h3>
|
|
<a id="s3.8" name="s3.8"></a>3.8 OWL Lite Header Information
|
|
</h3>OWL Lite supports notions of ontology inclusion and
|
|
relationships and attaching information to ontologies.
|
|
<!-- dlm: removed specificity of section previously included
|
|
OWL supports
|
|
standard notions of ontology referencing, inclusion, and meta-information. All
|
|
three levels of OWL include ways of specifying ontologies to import, ontology
|
|
version information, prior ontology version information, ontologies known to be
|
|
backward compatible, and ontologies known to be incompatible.
|
|
-->See the
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-ref-20030818/">OWL
|
|
Reference</a> for details and the
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/">OWL
|
|
Guide</a> for examples.
|
|
<h3>
|
|
<a id="s3.9" name="s3.9"></a>3.9 OWL Lite Annotation
|
|
Properties
|
|
</h3>OWL Lite allows annotations on classes, properties,
|
|
individuals and ontology headers. The use of these annotations
|
|
is subject to certain restrictions. See the
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-ref-20030818/#Annotations">section on
|
|
Annotations in the OWL Reference</a> for details.
|
|
<h3>
|
|
<a id="s3.10" name="s3.10"></a>3.10 OWL Lite Versioning
|
|
</h3>RDF already has a small vocabulary for describing
|
|
versioning information. OWL significantly extends this
|
|
vocabulary. See the
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-ref-20030818/#Header">OWL
|
|
Reference</a> for further details.
|
|
<h2>
|
|
<a id="s4" name="s4"></a>4. Incremental Language Description
|
|
of OWL DL and OWL FULL
|
|
</h2>Both OWL DL and OWL Full use the same vocabulary although
|
|
OWL DL is subject to some restrictions. Roughly, OWL DL
|
|
requires type separation (a class can not also be an individual
|
|
or property, a property can not also be an individual or
|
|
class). This implies that restrictions cannot be applied to the
|
|
language elements of OWL itself (something that is allowed in
|
|
OWL Full). Furthermore, OWL DL requires that properties are
|
|
either ObjectProperties or DatatypeProperties:
|
|
DatatypeProperties are relations between instances of classes
|
|
and RDF literals and XML Schema datatypes, while
|
|
ObjectProperties are relations between instances of two
|
|
classes. The
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-semantics-20030818/">OWL
|
|
Semantics and Abstract Syntax</a> document explains the
|
|
distinctions and limitations. We describe the OWL DL and OWL
|
|
Full vocabulary that extends the constructions of OWL Lite
|
|
below.
|
|
<ul>
|
|
<li>
|
|
<b><i><a id="oneOf" name="oneOf"></a>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#owl_oneOf">oneOf</a></i></b>:
|
|
(enumerated classes): Classes can be described by
|
|
enumeration of the individuals that make up the class. The
|
|
members of the class are exactly the set of enumerated
|
|
individuals; no more, no less. For example, the class of
|
|
daysOfTheWeek can be described by simply enumerating the
|
|
individuals Sunday, Monday, Tuesday, Wednesday, Thursday,
|
|
Friday, Saturday. From this a reasoner can deduce the
|
|
maximum cardinality (7) of any property that has
|
|
daysOfTheWeek as its allValuesFrom restriction.
|
|
</li>
|
|
<li>
|
|
<b><i><a id="hasValue" name="hasValue"></a>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#owl_hasValue">hasValue</a></i></b>:
|
|
(property values): A property can be required to have a
|
|
certain individual as a value (also sometimes referred to
|
|
as property values). For example, instances of the class of
|
|
dutchCitizens can be characterized as those people that
|
|
have theNetherlands as a value of their nationality.
|
|
(TheNetherlands itself is an instance of the class of
|
|
Nationalities).
|
|
</li>
|
|
<li>
|
|
<b><i><a id="disjointWith" name="disjointWith"></a>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#owl_disjointWith">disjointWith</a></i></b>:
|
|
OWL Full allows the statement that classes are disjoint.
|
|
For example, Man and Woman can be stated to be disjoint
|
|
classes. From this disjointWith statement, a reasoner can
|
|
deduce an inconsistency when an individual is stated to be
|
|
an instance of both and similarly a reasoner can deduce
|
|
that if A is an instance of Man, then A is <i>not</i> an
|
|
instance of Woman.
|
|
</li>
|
|
<li>
|
|
<b><i><a id="booleanFull" name="booleanFull"></a>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#owl_unionOf">unionOf,
|
|
complementOf, intersectionOf</a></i></b> (Boolean
|
|
combinations): OWL DL allows arbitrary Boolean combinations
|
|
of classes and restrictions: unionOf, complementOf, and
|
|
intersectionOf. For example, using unionOf, we can state
|
|
that a class contains things that are either USCitizens or
|
|
DutchCitizens. Using complementOf, we could state that
|
|
children are <i>not</i> SeniorCitizens. (i.e. the class
|
|
Children is a subclass of the complement of
|
|
SeniorCitizens). Citizenship of the European Union could be
|
|
described as the union of the citizenship of all member
|
|
states.
|
|
</li>
|
|
<li>
|
|
<b><i><a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/#owl_cardinality">
|
|
minCardinality, maxCardinality,
|
|
cardinality</a><a id="cardinalityFull"
|
|
name="cardinalityFull"></a></i></b> (full cardinality):
|
|
While in OWL Lite, cardinalities are restricted to at
|
|
least, at most or exactly 1 or 0, full OWL allows
|
|
cardinality statements for arbitrary non-negative integers.
|
|
For example the class of DINKs ("Dual Income, No Kids")
|
|
would restrict the cardinality of the property hasIncome to
|
|
a minimum cardinality of two (while the property hasChild
|
|
would have be restricted to cardinality 0).
|
|
</li>
|
|
<li>
|
|
<b><i><a id="complexClassFull"
|
|
name="complexClassFull">complex classes</a></i></b> : In
|
|
many constructs, OWL Lite restricts the syntax to single
|
|
class names (e.g. in subClassOf or equivalentClass
|
|
statements). OWL Full extends this restriction to allow
|
|
arbitrarily complex class descriptions, consisting of
|
|
enumerated classes, property restrictions, and Boolean
|
|
combinations. Also, OWL Full allows classes to be used as
|
|
instances (and OWL DL and OWL Lite do not). For more on
|
|
this topic, see the "Design for Use" section of the Guide
|
|
document.
|
|
</li>
|
|
</ul>
|
|
<h2>
|
|
<a id="s5" name="s5">5. Summary</a>
|
|
</h2>This document provides an overview of the Web Ontology
|
|
Language by providing a brief introduction to why one might
|
|
need a Web ontology language and how OWL fits in with related
|
|
W3C languages. It also provides a brief description of the
|
|
three OWL sublanguages: OWL Lite, OWL DL, and OWL Full along
|
|
with a feature synopsis for each of the languages. This
|
|
document is an update to the Feature Synopsis Document. It
|
|
provides simple descriptions of the constructs along with
|
|
simple examples. It references the
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-ref-20030818/">OWL
|
|
reference</a> document, the
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/">OWL
|
|
Guide</a>, and the
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-semantics-20030818/">OWL
|
|
Semantics and Abstract Syntax</a> document for more details.
|
|
Previous versions (
|
|
<a href="http://www.ksl.stanford.edu/people/dlm/webont/OWLOverviewJuly302003.htm">
|
|
July 30, 2003</a>,
|
|
<a href="http://www.ksl.stanford.edu/people/dlm/webont/OWLOverviewMay12003.htm">
|
|
May 1, 2003</a>,
|
|
<a href="http://www.ksl.stanford.edu/people/dlm/webont/OWLFeatureSynopsisMarch202003.htm">
|
|
March 20, 2003</a>,
|
|
<a href="http://www.ksl.stanford.edu/people/dlm/webont/OWLFeatureSynopsisJan22003.htm">
|
|
January 2, 2003</a>,
|
|
<a href="http://www.ksl.stanford.edu/people/dlm/webont/OWLFeatureSynopsisJuly29.htm">
|
|
July 29, 2002</a>,
|
|
<a href="http://www.ksl.stanford.edu/people/dlm/webont/OWLFeatureSynopsisJuly8.htm">
|
|
July 8, 2002</a>,
|
|
<a href="http://www.ksl.stanford.edu/people/dlm/webont/OWLFeatureSynopsisJune23.htm">
|
|
June 23, 2002</a>,
|
|
<a href="http://www.ksl.stanford.edu/people/dlm/webont/complianceMay262002.html">
|
|
May 26, 2002</a>, and
|
|
<a href="http://www.ksl.stanford.edu/people/dlm/webont/complianceMay152002.html">
|
|
May 15, 2002</a>) of this document provide the historical view
|
|
of the evolution of OWL Lite and the issues discussed in its
|
|
evolution.
|
|
<h2>
|
|
<a id="s6" name="s6">References</a>
|
|
</h2>
|
|
<dl>
|
|
<dt>
|
|
<a name="Guide" id="Guide">OWL Guide</a>
|
|
</dt>
|
|
<dd>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-guide-20030818/"><cite>
|
|
OWL Web Ontology Language Guide</cite></a>. Mike Smith,
|
|
Chris Welty, and Deborah L. McGuinness. W3C Candidate
|
|
Recommendation 18 August 2003.<br />
|
|
<br />
|
|
</dd>
|
|
<dt>
|
|
<a name="SyntaxandSemantics" id="SyntaxandSemantics">OWL
|
|
Abstract Syntax and Semantics</a>
|
|
</dt>
|
|
<dd>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-semantics-20030818/">
|
|
<cite>OWL Web Ontology Language Semantics and Abstract
|
|
Syntax</cite></a>, Peter F. Patel-Schneider, Patrick Hayes,
|
|
and Ian Horrocks. W3C Candidate Recommendation 18 August
|
|
2003.<br />
|
|
<br />
|
|
</dd>
|
|
<dt>
|
|
<a name="Reference" id="Reference">OWL Reference</a>
|
|
</dt>
|
|
<dd>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-ref-20030818/"><cite>
|
|
OWL Web Ontology Language Reference</cite></a>. Mike Dean,
|
|
Guus Schreiber, Sean Bechhofer, Frank van Harmelen, Jim
|
|
Hendler, Ian Horrocks, Deborah L. McGuinness, Peter F.
|
|
Patel-Schneider, and Lynn Andrea Stein. W3C Candidate
|
|
Recommendation 18 August 2003.<br />
|
|
<br />
|
|
</dd>
|
|
<dt>
|
|
<a name="Overview" id="Overview">OWL Overview</a>
|
|
</dt>
|
|
<dd>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-features-20030818/">
|
|
<cite>OWL Web Ontology Language Overview</cite></a>.
|
|
Deborah L. McGuinness and Frank van Harmelen. W3C Candidate
|
|
Recommendation 18 August 2003.<br />
|
|
<br />
|
|
</dd>
|
|
<dt>
|
|
<a name="OwlTest" id="OwlTest">OWL Test</a>
|
|
</dt>
|
|
<dd>
|
|
<a href="http://www.w3.org/TR/2003/CR-owl-test-20030818/"><cite>
|
|
OWL Web Ontology Language Test Cases</cite></a>. Jeremy J.
|
|
Carroll and Jos De Roo. W3C Candidate Recommendation 18
|
|
August 2003.<br />
|
|
<br />
|
|
</dd>
|
|
<dt>
|
|
<a name="Issues" id="Issues">OWL Issues</a>
|
|
</dt>
|
|
<dd>
|
|
<a href="http://www.w3.org/2001/sw/WebOnt/webont-issues.html">
|
|
<cite>Web Ontology Issue Status</cite></a>. Michael K.
|
|
Smith, ed. 27 June 2003.<br />
|
|
<br />
|
|
</dd>
|
|
<dt>
|
|
<a name="Requirements" id="Requirements">OWL
|
|
Requirements</a>
|
|
</dt>
|
|
<dd>
|
|
<a href="http://www.w3.org/TR/2003/CR-webont-req-20030818/">
|
|
<cite>OWL Web Ontology Language Use Cases and
|
|
Requirements</cite></a>. Jeff Heflin. W3C Candidate
|
|
Recommendation 18 August 2003.<br />
|
|
<br />
|
|
</dd>
|
|
<dt>
|
|
<a name="DAMLReference" id="DAMLReference">DAML+OIL
|
|
Reference</a>
|
|
</dt>
|
|
<dd>
|
|
<a href="http://www.w3.org/TR/daml+oil-reference"><cite>DAML+OIL
|
|
Reference Description</cite></a> . Dan Connolly, Frank van
|
|
Harmelen, Ian Horrocks, Deborah L. McGuinness, Peter F.
|
|
Patel-Schneider, and Lynn Andrea Stein. W3C Note 18
|
|
December 2001.<br />
|
|
<br />
|
|
</dd>
|
|
<dt>
|
|
<a id="XML" name="XML">XML</a>
|
|
</dt>
|
|
<dd>
|
|
<a href="http://www.w3.org/XML/"><cite>Extensible Markup
|
|
Language (XML)</cite> .</a><br />
|
|
<br />
|
|
</dd>
|
|
<dt>
|
|
<a id="XMLSchema" name="XMLSchema">XML Schema</a>
|
|
</dt>
|
|
<dd>
|
|
<a href="http://www.w3.org/XML/Schema"><cite>XML
|
|
Schema</cite> .</a><br />
|
|
<br />
|
|
</dd>
|
|
<dt>
|
|
<a name="RDF" id="RDF">RDF</a>
|
|
</dt>
|
|
<dd>
|
|
<a href="http://www.w3.org/TR/2002/WD-rdf-concepts-20021108/">
|
|
<cite>Resource Description Frameswork (RDF): Concepts and
|
|
Abstract Syntax</cite></a>. Grahm Klyne and Jeremy Carroll.
|
|
W3C Working Draft, November 2002.<br />
|
|
<br />
|
|
</dd>
|
|
<dt>
|
|
<a id="RDFSchema" name="RDFSchema">RDF Schema</a>
|
|
</dt>
|
|
<dd>
|
|
<a href="http://www.w3.org/TR/2003/WD-rdf-schema-20030123/"><cite>RDF
|
|
Vocabulary Description Language 1.0: RDF Schema.</cite></a>
|
|
Dan Brickley and R. V. Guha. W3C Working Draft 23 January
|
|
2003.<br />
|
|
<br />
|
|
</dd>
|
|
<dt>
|
|
<a name="DescriptionLogics"
|
|
id="DescriptionLogics">Description Logics</a>
|
|
</dt>
|
|
<dd>
|
|
<a href="http://books.cambridge.org/0521781760.htm"><cite>The
|
|
Description Logic Handbook</cite></a>. Franz Baader, Diego
|
|
Calvanese, Deborah McGuinness, Daniele Nardi, Peter
|
|
Patel-Schneider, editors. Cambridge University Press, 2003;
|
|
and<br />
|
|
</dd>
|
|
<dd>
|
|
<a href="http://dl.kr.org"><cite>Description Logics Home
|
|
Page</cite></a>.<br />
|
|
<br />
|
|
</dd>
|
|
<dd>
|
|
<br />
|
|
</dd>
|
|
</dl>
|
|
<h2>
|
|
<a id="s7" name="s7">Acknowledgements</a>
|
|
</h2>This document is the result of extensive discussions
|
|
within the Web Ontology Working Group as a whole. The members
|
|
of this working group were Jean-François Baget,
|
|
James Barnette, Sean Bechhofer, Jonathan Borden, Frederik
|
|
Brysse, Stephen Buswell, Jeremy Carroll, Dan Connolly, Peter
|
|
Crowther, Jonathan Dale, Jos De Roo, David De Roure, Mike Dean,
|
|
Larry Eshelman, JérômeEuzenat, Dieter
|
|
Fensel, Tim Finin, Nicholas Gibbins, Sandro Hawke,
|
|
Pat Hayes, Jeff Heflin,
|
|
Ziv Hellman, James Hendler, Bernard Horan, Masahiro Hori, Ian
|
|
Horrocks, Francesco Iannuzzelli, Mario Jeckle, Ruediger Klein,
|
|
Natasha Kravtsova, Ora Lassila, Alexander Maedche, Massimo
|
|
Marchiori, Deborah McGuinness, Libby Miller, Enrico Motta, Leo
|
|
Obrst, Laurent Olivry , Peter Patel-Schneider, Martin Pike,
|
|
Marwan Sabbouh, Guus Schreiber, Noboru Shimizu, Michael Sintek,
|
|
Michael Smith, Ned Smith, John Stanton, Lynn Andrea Stein,
|
|
Herman ter Horst, Lynne R. Thompson, David Trastour, Frank van
|
|
Harmelen, Raphael Volz, Evan Wallace, Christopher Welty,
|
|
Charles White, and John Yanosy.
|
|
<h2>
|
|
<a id="s8" name="s8">Change Log Since Last Call Release</a>
|
|
</h2>
|
|
<ul>
|
|
<li>
|
|
Added owl:Nothing to OWL Lite.
|
|
</li>
|
|
<li>
|
|
Added pointer to last call document under title
|
|
</li>
|
|
<li>
|
|
Changed all links to owl-absyn to owl-semantics
|
|
</li>
|
|
<li>
|
|
Incorporated Lee Lacy's grammatical comments from
|
|
public-webont-comments dated April 21, 2003.
|
|
</li>
|
|
<li>
|
|
Incorporated Lee Lacy's other comments: annotation
|
|
properties, version properties, and other missing tags in
|
|
2.2 (which got reorganised as a result)
|
|
</li>
|
|
<li>
|
|
changed hasOffSpring example to hasDaughter (request of
|
|
Morten Frederiksen)
|
|
</li>
|
|
<li>
|
|
incorporated all Lasilla's comment, including replacing
|
|
"machine readability" by "machine interpretability" and
|
|
various typo's.
|
|
</li>
|
|
<li>
|
|
Added sentence on lower complexity class of OWL Lite, as
|
|
proposed by Jim Hendler
|
|
</li>
|
|
<li>
|
|
Added first sentence to section 1, after Sandro Hawke's
|
|
comment
|
|
</li>
|
|
<li>
|
|
Restored link to style file
|
|
</li>
|
|
<li>
|
|
Added link to test document and May 1 version
|
|
</li>
|
|
<li>
|
|
Added references section
|
|
</li>
|
|
<li>
|
|
Changed back to relative references to sections
|
|
</li>
|
|
<li>
|
|
Changed links to http://www.w3.org/TR/xx from previous
|
|
versions with updates later to ...TR/2003/CR-xx-20030818/
|
|
</li>
|
|
</ul>
|
|
</body>
|
|
</html>
|