Hi<br><br>As some of you know, I'm using Drools as an engine for N3 logic (<a href="http://www.w3.org/2000/10/swap/doc/Rules">http://www.w3.org/2000/10/swap/doc/Rules</a>) .<br>N3 is a language equivalent to Semantic Web's RDF language, but much easier to read and write by hand.<br>
Moreover, N3 has, on top of RDF, an extension for rules, e.g. :<br><pre>{ ?x parent ?y } => { ?y child ?x }.</pre>Among many other vocabularies searchable on search site Swoogle (<a href="http://swoogle.umbc.edu/">http://swoogle.umbc.edu/</a>), there is OWL, (OWL Web Ontology Language) that allows to express in RDF, and thus in N3, rich models with classes, properties, inheritance and constraints. <br>
So in summary, N3 is a user-friendly language allowing to express facts, class and properties, and rules.<br><br>So what does that bring for Drools users ?<br>One use case :<br>- open any number of RDF / OWL / N3 documents<br>
- test and debug the rules using 3 rule engines (Drools, Euler, CWM)<br>- export all that project as a set of Drools packages, plus the facts in XMLEncoder format ( by clicking on File / "Export as Drools" )<br>
<br>You can also use standard Semantic Web tools such as Protégé and Swoop to edit and visualize RDF and OWL files.<br><br>Moreover, there are, as part of the Euler project, a library of N3 rules that implement the logic of OWL and RDF Schema (transitive property, inheritance, etc), and other goodies, see:<br>
<a href="http://eulersharp.svn.sourceforge.net/viewvc/eulersharp/trunk/2003/03swap/rpo-rules.n3">http://eulersharp.svn.sourceforge.net/viewvc/eulersharp/trunk/2003/03swap/rpo-rules.n3</a><br><br>I translate N3 logic into Drools language, using just two classes corresponding to Triple
(statement) (
explanations here : <a href="http://eulergui.svn.sourceforge.net/viewvc/eulergui/trunk/eulergui/html/documentation.html#Translatin">http://eulergui.svn.sourceforge.net/viewvc/eulergui/trunk/eulergui/html/documentation.html#Translatin</a>
).<br><br>Download from<br><a href="https://sourceforge.net/projects/eulergui">https://sourceforge.net/projects/eulergui</a><br><br>Manual here:<br><a href="http://eulergui.svn.sourceforge.net/viewvc/eulergui/trunk/eulergui/html/documentation.html">http://eulergui.svn.sourceforge.net/viewvc/eulergui/trunk/eulergui/html/documentation.html</a><br>
<br>Enjoy !<br><br>I've been working on this for several months, so it's beginning to stabilize. But the rich set of built-in functions for other N3 engines is still missing, with a few exceptions.<br><br>I'm using this framework currently to generate GUI's from domain models ( rules are here : <a href="http://deductions.svn.sourceforge.net/viewvc/deductions/n3/">http://deductions.svn.sourceforge.net/viewvc/deductions/n3/</a> ).<br>
You will be glad to read that it runs around 2 seconds including compilation, compared to the other engine (in Prolog) I use, which need hundreds of seconds (actually a high complexity). A forward chaining engine seems to make sense for such a constructive task.<br>
<br>I also wrote a How To about what I do currently with EulerGUI :<br>Deduction project - Java Swing application generator from OWL model and N3 logic rules<br><a href="http://deductions.svn.sourceforge.net/viewvc/deductions/html/GUIgenerator.html">http://deductions.svn.sourceforge.net/viewvc/deductions/html/GUIgenerator.html</a><br>
Deduction project is work in progress.<br><br>-- <br>Jean-Marc Vanel<br><a href="http://jmvanel.free.fr/">http://jmvanel.free.fr/</a><br>