Semantic Web Rule Language

<h2 id="example">Example</h2>
<h3>Human Readable Syntax</h3>
hasParent(?x1,?x2) ∧ hasBrother(?x2,?x3) ⇒ hasUncle(?x1,?x3)

<h3>XML Concrete Syntax</h3>
<p>The <a href="/facts/XML/clNgUfWk">XML</a> Concrete Syntax is a combination of the <i>OWL Web Ontology Language XML Presentation Syntax</i> with the <i>RuleML XML syntax</i>.
</p>
 <ruleml:imp> 
  <ruleml:_rlab ruleml:href="#example1"/>
  <ruleml:_body> 
    <swrlx:individualPropertyAtom  swrlx:property="hasParent"> 
      <ruleml:var>x1</ruleml:var>
      <ruleml:var>x2</ruleml:var>
    </swrlx:individualPropertyAtom> 
    <swrlx:individualPropertyAtom  swrlx:property="hasBrother"> 
      <ruleml:var>x2</ruleml:var>
      <ruleml:var>x3</ruleml:var>
    </swrlx:individualPropertyAtom> 
  </ruleml:_body> 
  <ruleml:_head> 
    <swrlx:individualPropertyAtom  swrlx:property="hasUncle"> 
      <ruleml:var>x1</ruleml:var>
      <ruleml:var>x3</ruleml:var>
    </swrlx:individualPropertyAtom> 
  </ruleml:_head> 
 </ruleml:imp>

<h3>RDF Concrete Syntax</h3>
<p>It is straightforward to provide such an <a href="/facts/Resource_Description_Framework/WMufyukm">RDF</a> concrete syntax for rules, but the presence of variables in rules goes beyond the RDF Semantics.<a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a> Translation from the XML Concrete Syntax to <a href="/facts/RDF/XML/vsRwLAVS">RDF/XML</a> could be easily accomplished by extending the <a href="/facts/XSLT/0gw4WVyJ">XSLT</a> transformation for the OWL XML Presentation syntax.
</p>
<h2 id="implementations">Implementations</h2>
<p>Caveat: Reasoners do not support the full specification because the reasoning becomes undecidable. There can be three types of approach: 
</p>
<ol><li>translate SWRL into First Order Logic (Hoolet) and demonstrate reasoning tasks with a theorem prover;</li>
<li>translate OWL-DL into rules and give the rules to a forward chaining engine (Bossam) (this approach cannot cover the full expressivity of OWL-DL due to many incompatibilities between Description Logic and Horn Rule formalisms)</li>
<li>expand an existing OWL-DL reasoner based on the tableaux algorithm (Pellet).</li>
<li><a href="/facts/Protege_(software)/IRJsReak">Protégé</a> 4.2 includes a Rules view in its Ontology Views that supports SWRL rules.</li>
<li>For older versions of Protégé, SWRLTab is an extension that supports editing and execution of SWRL rules. <a href="https://archive.today/20121215054848/http://protege.cim3.net/cgi-bin/wiki.pl?SWRLTab">[1]</a></li>
<li><a href="/facts/R2ML/NBj5fQLJ">R2ML</a> (REWERSE Rule Markup Language) supports SWRL. <a href="http://oxygen.informatik.tu-cottbus.de/rewerse-i1/?q=node/6">[2]</a></li>
<li>Bossam, a <a href="/facts/Forward_chaining/FJjYIf6S">forward chaining</a> rule engine supports SWRL. <a href="http://bossam.wordpress.com/">[3]</a></li>
<li>Hoolet, an implementation of an OWL-DL reasoner that uses a first order prover supports SWRL. <a href="http://owl.man.ac.uk/hoolet/">[4]</a></li>
<li>Pellet, an open-source Java OWL DL reasoner has SWRL-support. <a href="https://web.archive.org/web/20070925082014/http://pellet.owldl.com/">[5]</a></li>
<li>KAON2 is an infrastructure for managing OWL-DL, SWRL, and F-Logic ontologies. <a href="http://kaon2.semanticweb.org/">[6]</a></li>
<li>RacerPro, supports the processing of rules in a SWRL-based syntax by translating them into nRQL rules <a href="https://web.archive.org/web/20060718175210/http://www.racer-systems.com/products/racerpro/index.phtml">[7]</a></li>
<li>Stardog is an RDF database or <a href="/facts/Triplestore/k0e2ua9S">triplestore</a> that rewrites queries to answer questions using SWRL inferences. <a href="http://stardog.com/">[8]</a></li></ol>
<table><tbody><tr><th></th><th>Bossam</th><th>Hoolet</th><th>Pellet</th></tr><tr><th>SWRL/OWLX Parser</th><td>Yes</td><td>?</td><td>?</td></tr><tr><th>SWRL/RDF Parser</th><td>Yes</td><td>?</td><td>Yes</td></tr><tr><th>Math Built-Ins</th><td>Partial</td><td>?</td><td>Yes</td></tr><tr><th>String Built-Ins</th><td>Partial</td><td>?</td><td>Yes</td></tr><tr><th>Comparison Built-Ins</th><td>?</td><td>?</td><td>Yes</td></tr><tr><th>Boolean Built-Ins</th><td>?</td><td>?</td><td>Yes</td></tr><tr><th>Date, Time and Duration Built-Ins</th><td>?</td><td>?</td><td>No</td></tr><tr><th>URI Built-Ins</th><td>?</td><td>?</td><td>Yes</td></tr><tr><th>Lists Built-Ins</th><td>?</td><td>?</td><td>No</td></tr><tr><th>Licensing</th><td>Free/closed-source</td><td>Free/open-source</td><td>Free/open-source</td></tr></tbody></table>
<h2 id="comparison-with-description-logic-programs">Comparison with Description Logic Programs</h2>
<p>Description Logic Programs (DLPs) are another proposal for integrating rules and OWL.<a class="footnote-ref" id="fnref:7" href="#fn:7"><sup>7</sup></a>
Compared with Description Logic Programs, SWRL takes a diametrically opposed integration approach. DLP is the intersection of <a href="/facts/Horn_logic/3IRKqnp1">Horn logic</a> and OWL, whereas SWRL is (roughly) the union of them.<a class="footnote-ref" id="fnref:8" href="#fn:8"><sup>8</sup></a> In DLP, the resultant language is a very peculiar looking description logic and rather inexpressive language overall.<a class="footnote-ref" id="fnref:9" href="#fn:9"><sup>9</sup></a>
</p>
<h2 id="future-directions-and-applications-of-swrl">Future Directions and Applications of SWRL</h2>
<p>As the Semantic Web continues to evolve, the role of SWRL in enabling automated reasoning and decision-making processes will likely expand. While current implementations, such as those found in Protégé and Pellet, provide significant capabilities, ongoing advancements in artificial intelligence and knowledge representation may lead to even more sophisticated reasoning engines that better handle the computational complexities introduced by SWRL. Furthermore, as data integration across diverse domains becomes increasingly critical, SWRL could play a pivotal role in enhancing interoperability between systems that utilize OWL ontologies. The combination of rules with ontologies, as facilitated by SWRL, remains a powerful mechanism for drawing inferences and uncovering relationships in large, distributed datasets, offering broad applicability in fields such as healthcare, finance, and semantic data analytics.<a class="footnote-ref" id="fnref:10" href="#fn:10"><sup>10</sup></a>
</p>
<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/Description_Logic/9jpPaDsn">Description Logic</a></li>
<li><a href="/facts/Web_Ontology_Language/jkr0IGn8">Web Ontology Language</a> - "OWL"</li>
<li><a href="/facts/Datalog/67jbYWDb">Datalog</a> (query and rule language)</li>
<li><a href="/facts/Semantic_Web/NFHo9dB7">Semantic Web</a></li>
<li><a href="/facts/Semantic_Grid/lwLeqF6s">Semantic Grid</a></li>
<li><a href="/facts/Ontology_(information_science)/SQlhl6lp">Ontology (information science)</a></li>
<li><a href="/facts/Business_Intelligence_2.0/49rFTHXJ">Business Intelligence 2.0</a> (BI 2.0)</li>
<li><a href="/facts/Semantic_wiki/P0Ehtklg">Semantic wiki</a></li></ul>

<h2 id="external-links">External links</h2>
<ul><li><a href="http://www.w3.org/Submission/SWRL/">SWRL: A Semantic Web Rule Language Combining OWL and RuleML</a>, W3C Member Submission 21 May 2004</li>
<li><a href="http://www.w3.org/Submission/SWRL-FOL/">A Proposal for a SWRL Extension towards First-Order Logic</a>, W3C Member Submission 11 April 2005</li>
<li><a href="http://www.w3.org/TR/owl-xmlsyntax/">OWL Web Ontology Language XML Presentation Syntax</a>, W3C Note 11 June 2003</li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>Horrocks, Ian; Patel-Schneider, Peter F.; Boley, Harold; Tabet, Said; Grosof, Benjamin; Dean, Mike (21 May 2004). "SWRL: A Semantic Web Rule Language Combining OWL and RuleML". W3C. Retrieved 21 December 2017. <a href="https://www.w3.org/Submission/SWRL/" target="_blank">https://www.w3.org/Submission/SWRL/</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
<li id="fn:2"><p>Ian Horrocks; Peter F. Patel-Schneider (2004). "A Proposal for an OWL Rules Language" (PDF). Proc. of the Thirteenth International World Wide Web Conference (WWW 2004). ACM. pp. 723–731. Retrieved 22 May 2014. <a href="http://www.cs.ox.ac.uk/people/ian.horrocks/Publications/download/2004/HoPa04a.pdf" target="_blank">http://www.cs.ox.ac.uk/people/ian.horrocks/Publications/download/2004/HoPa04a.pdf</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li>
<li id="fn:3"><p>Ian Horrocks; Peter F. Patel-Schneider; Sean Bechhofer; Dmitry Tsarkov (2005). "OWL Rules: A Proposal and Prototype Implementation" (PDF). Journal of Web Semantics. 3 (1). Elsevier: 23–40. doi:10.1016/j.websem.2005.05.003. Retrieved 22 May 2014. <a href="http://www.cs.ox.ac.uk/people/ian.horrocks/Publications/download/2005/HPBT05.pdf" target="_blank">http://www.cs.ox.ac.uk/people/ian.horrocks/Publications/download/2005/HPBT05.pdf</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li>
<li id="fn:4"><p>Bijan Parsia; et al. (2005). "Cautiously Approaching SWRL" (PDF). Retrieved 29 July 2006. {{cite journal}}: Cite journal requires |journal= (help) <a href="https://cs.uwaterloo.ca/~gweddell/cs848/SWRL_Parsia_et_al.pdf" target="_blank">https://cs.uwaterloo.ca/~gweddell/cs848/SWRL_Parsia_et_al.pdf</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li>
<li id="fn:5"><p>Boris Motik; Ulrike Sattler; Rudi Studer (2005). "Query Answering for OWL-DL with Rules" (PDF). Journal of Web Semantics. 3 (1). Elsevier: 41–60. doi:10.1016/j.websem.2005.05.001. Retrieved 22 May 2014. <a href="http://www.cs.ox.ac.uk/boris.motik/pubs/mss05query-journal.pdf" target="_blank">http://www.cs.ox.ac.uk/boris.motik/pubs/mss05query-journal.pdf</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li>
<li id="fn:6"><p>Mei, Jing; Harold Boley (2006). "Interpreting SWRL Rules in RDF Graphs" (PDF). Electronic Notes in Theoretical Computer Science. 151 (2). Elsevier: 53–69. doi:10.1016/j.entcs.2005.07.036. S2CID 14325289. Retrieved 29 July 2006. <a href="http://www.is.pku.edu.cn/~mayyam/papers/Interpreting%20SWRL%20Rules%20in%20RDF%20Graphs.pdf" target="_blank">http://www.is.pku.edu.cn/~mayyam/papers/Interpreting%20SWRL%20Rules%20in%20RDF%20Graphs.pdf</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li>
<li id="fn:7"><p>Benjamin N. Grosof; Ian Horrocks; Raphael Volz; Stefan Decker (2003). "Description Logic Programs: Combining Logic Programs with Description Logic" (PDF). Proc. of the Twelfth International World Wide Web Conference (WWW 2003). ACM. pp. 48–57. Retrieved 22 May 2014. <a href="http://www.cs.ox.ac.uk/people/ian.horrocks/Publications/download/2003/p117-grosof.pdf" target="_blank">http://www.cs.ox.ac.uk/people/ian.horrocks/Publications/download/2003/p117-grosof.pdf</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></p></li>
<li id="fn:8"><p>Bijan Parsia; et al. (2005). "Cautiously Approaching SWRL" (PDF). Retrieved 29 July 2006. {{cite journal}}: Cite journal requires |journal= (help) <a href="https://cs.uwaterloo.ca/~gweddell/cs848/SWRL_Parsia_et_al.pdf" target="_blank">https://cs.uwaterloo.ca/~gweddell/cs848/SWRL_Parsia_et_al.pdf</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></p></li>
<li id="fn:9"><p>Bijan Parsia; et al. (2005). "Cautiously Approaching SWRL" (PDF). Retrieved 29 July 2006. {{cite journal}}: Cite journal requires |journal= (help) <a href="https://cs.uwaterloo.ca/~gweddell/cs848/SWRL_Parsia_et_al.pdf" target="_blank">https://cs.uwaterloo.ca/~gweddell/cs848/SWRL_Parsia_et_al.pdf</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></p></li>
<li id="fn:10"><p>"OWL - Semantic Web Standards". www.w3.org. Retrieved 13 September 2024. <a href="https://www.w3.org/OWL/" target="_blank">https://www.w3.org/OWL/</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></p></li>
</ol>

Semantic Web Rule Language open-in-new

Semantic Web Rule Language