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Re: exchanging OWL through RIF

From: Ed Barkmeyer <edbark@nist.gov>
Date: Fri, 03 Mar 2006 11:27:24 -0500
Message-ID: <44086E6C.6020902@nist.gov>
To: Dave Reynolds <der@hplb.hpl.hp.com>
CC: RIF WG <public-rif-wg@w3.org>

Dave,

I think we actually agree, and you further corrected what I erroneously copied.

Michael Kifer wrote:

>>> I am having a second thought about the requirement that OWL should be
>>> exchangeable through RIF by encoding it in FOL ...

I wrote:

>> It is not a matter of "exchanging an OWL ontology"; the requirement is 
>> to deliver the semantic content of an OWL ontology as a ruleset, so 
>> that a rules engine can incorporate that content into its rulebase.

And unfortunately I also said:

>> ... And the 
>> requirement for RIF is that its "FOL subset" be able to capture the 
>> semantics of the OWL ontology.

You wrote:

> No I must disagree there.
> 
> To take your specific examples, Jena does not implement FOL and I wasn't 
> aware that ILOG did.
>
> If the ontology remains in OWL then, for example, a Jena user can 
> continue to chose between a rule based approximation to OWL or calling 
> out to a DL reasoner. 

The wording "FOL subset" here is misleading, but it may be that that is the 
crux of the issue.  I didn't intend to imply that any rules engine actually 
process "first-order logic" in the classical sense, or any "FOL subset" per 
se.  The "rule-based approximation to OWL" is what I meant.  It may contain 
statements that *are* FOL assertions, and it may contain other statements that 
*look like* FOL postulates, but have an importantly different underlying model 
that is only sometimes consistent with the FOL interpretation.  For example, I 
might expect an OWL "definition" to become a "directed inference".

I don't believe that RIF (unlike RuleML) needs an "FOL subset" per se.  As 
Michael says, we already have OWL for DLs and ISO Common Logic for FOLs.  We 
need to concentrate on an exchange language that has one consistent semantic 
model.  I do believe that we need to at least address the question of 
exchanging "rule-based approximations" of OWL ontologies, in addition to 
"intelligent access" to OWL and RDF knowledge bases.

Jim Hendler's NCI use-case is the kind of thing I had in mind:  Converting 
elements of a medical ontology into a useful diagnostic tool for a medical 
specialist, where the diagnostic tool may well be Jena-based (or Blaze-based, 
or JRules-based, etc., etc., and I think all 3 of you actually have customers 
with such tools).

-Ed

-- 
Edward J. Barkmeyer                        Email: edbark@nist.gov
National Institute of Standards & Technology
Manufacturing Systems Integration Division
100 Bureau Drive, Stop 8263                Tel: +1 301-975-3528
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"The opinions expressed above do not reflect consensus of NIST,
  and have not been reviewed by any Government authority."
Received on Friday, 3 March 2006 16:27:42 GMT

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