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RE: here's a list of companies/organizations potentially interested Re: Rules WG -- draft charter

From: Minsu Jang <minsu@etri.re.kr>
Date: Tue, 11 Nov 2003 11:51:38 +0900
To: "'Dan Brickley'" <danbri@w3.org>
Cc: <www-rdf-rules@w3.org>
Message-ID: <000001c3a7fe$bd261ff0$8c4bfe81@ZEBEHN>

[Dan Brickley wrote,]
> * Minsu Jang <minsu@etri.re.kr> [2003-11-08 14:26+0900]
> > - OWLer: an OWL inference system. It uses JTP for inferencing.
> > - ezOWL: a Protege plugin for visual editing of OWL documents.
> > - MOA: a merging tool for merging multiple OWL ongologies.
> > - Buchingae: a web-friendly rule language. not XML-based.
> > - LogicML: a rule markup language, which is a slight extension of
> > RuleML's hornlog.
> 
> ...same question as above! Where/when can we find out more? 
> 

Most of these are not documented well yet, but ezOWL is
published under plugins directory of Protege.
You can find more about the plugin at http://iweb.etri.re.kr/ezowl/.

> I notice in
http://machine-knows.etri.re.kr/bossam/download/download.html that
> the engine isn't public yet. Do you have a sense for when it will be
> available, or expectations about likely license terms? (opensource
would
> be great...)

The engine will be available with the similar licensing terms to that of
Jess.

>
> A technical question (for everyone, really): 
> The Web Ontology WG spent a lot of time and energy 
> on the delicate balance between OWL DL and OWL Full. Do you have any
> findings from your implementation work that would help us estimate the

> impact of this aspect of OWL on any future Rules standardisation? Is 
> it feasible to keep both traditions/approaches/communities happy
within
> a single "OWL-compatible" rules language? 
>

I don't have good technical background on computational logics or
mechanical theorem proving, so what I'm going to say could be
a disaster for this list. ;-) Even if so, please don't hrurry for
escaping,
but be generous enough to provide your invaluable teachings.

Bossam is just a production rule system with some extended knowledge
representation elements which make the engine suitable for inferencing
over OWL ontology. When I started to write OWL inferencing rules, I did
not
fully understand what makes OWL Full and OWL DL different.

The only thing I knew was that OWL properties, classes and individuals
are
pairwise disjoint in OWL DL, but interchangeable in OWL Full.
This discrimination rule should be reflected in OWL inferencing rules
for OWL DL.
For OWL Full, all the facts and rules of RDFS should be added, and OWL
class
should be declared to be owl:equivalentClass to rdfs:Class.

What I have found until now is that the expressiveness of rule language
is
not very different whether it's for reasoning over OWL Lite, DL or Full.
The difference lies in the rulebases. When you write a rulebase
for reasoning over OWL Lite ontology, you will end up with a smaller set
of rules.

What I have in mind from my implementation experiences is that 
a single rules language is enough for OWL inference.

One thing I'd like to address at this point is that when you start to
write
rules for real applications, the situation becomes very complex.
It's not OWL inferencing, but real knowledge processing. The web is open
and many web users will want to process knowledge in the open web, which
will contain many knowledge elements which contradict each other.
Even if you preset all the ontologies for a reasoning session, the
situation
does not become more optimistic, because web ontologies are not
controlled.
Web ontologies *should* independently evolve.
In this regard, I think rule languages and processors for the semantic
web
should address problems of reasoning in the open knowledge space,
which is non-monotonic in its nature.

> BTW http://machine-knows.etri.re.kr/bossam/docs/owlinference.html
doesn't 
> explicitly mention OWL DL vs Full or Lite. Which flavour(s) are you
> targetting?

Um, I did not target any one species (:-\), but the rulebase I'm working
on is
targetting OWL Full. And I have a plan to write two more sets of rules
for
OWL DL and Lite.

Regards,
Minsu
Received on Monday, 10 November 2003 21:51:51 UTC

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