Hi
As some of you know, I'm using Drools as an engine for N3 logic (
http://www.w3.org/2000/10/swap/doc/Rules) .
N3 is a language equivalent to Semantic Web's RDF language, but much easier
to read and write by hand.
Moreover, N3 has, on top of RDF, an extension for rules, e.g. :
{ ?x parent ?y } => { ?y child ?x }.
Among many other vocabularies searchable on search site Swoogle (
http://swoogle.umbc.edu/), 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.
So in summary, N3 is a user-friendly language allowing to express facts,
class and properties, and rules.
So what does that bring for Drools users ?
One use case :
- open any number of RDF / OWL / N3 documents
- test and debug the rules using 3 rule engines (Drools, Euler, CWM)
- export all that project as a set of Drools packages, plus the facts in
XMLEncoder format ( by clicking on File / "Export as Drools" )
You can also use standard Semantic Web tools such as Protégé and Swoop to
edit and visualize RDF and OWL files.
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:
http://eulersharp.svn.sourceforge.net/viewvc/eulersharp/trunk/2003/03swap...
I translate N3 logic into Drools language, using just two classes
corresponding to Triple (statement) ( explanations here :
http://eulergui.svn.sourceforge.net/viewvc/eulergui/trunk/eulergui/html/d...).
Download from
https://sourceforge.net/projects/eulergui
Manual here:
http://eulergui.svn.sourceforge.net/viewvc/eulergui/trunk/eulergui/html/d...
Enjoy !
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.
I'm using this framework currently to generate GUI's from domain models (
rules are here :
http://deductions.svn.sourceforge.net/viewvc/deductions/n3/).
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.
I also wrote a How To about what I do currently with EulerGUI :
Deduction project - Java Swing application generator from OWL model and N3
logic rules
http://deductions.svn.sourceforge.net/viewvc/deductions/html/GUIgenerator...
Deduction project is work in progress.
--
Jean-Marc Vanel
http://jmvanel.free.fr/