Re: OWLLisaKB: an OWL reasoner written in Common Lisp.

Peter Seibel <[email protected]> writes:

> Yarden Katz <[email protected]> writes:
>
>> Hi guys,
>> 
>>   This is my first real post here--I hope this announcement is at
>>   least somewhat relevant/topical here :).
>
>>   I wrote a rule-based OWL reasoner (as part of Semantic Web
>>   research at http://owl.mindswap.org) in Common Lisp.
>
> Maybe you can give us--or those of us who don't know--the executive
> summary of what a OWL reasoner is and what one might do with it?

Sure.  OWL (Web Ontology Language) is a description logic
used to create ontologies on the Web.  For a gentle intro to OWL, see
<http://www.w3.org/TR/owl-guide/>.

An "ontology" is a term borrowed from philosophy that means, in the context of the
Semantic Web, a document defining a group of concepts (and roles[1])
and their relationship to each other and outside concepts.  An
ontology might represent, for example, that "Programmers and owners of
websites are people."

An OWL reasoner would then be used to infer that if Peter is an owner
of a website, or if Peter is a programmer, then Peter is also a
person.  Obviously much more complex reasoning is needed as the
ontologies grow in sophistication and size.

OWL was preceded by DAML+OIL, another description logic for the web,
and their syntaxes are essentially the same.  For examples of some
DAML+OIL ontologies see <http://www.daml.org/ontologies/>.  My reasoner also has a
module named DAMLLisaKB, which does DAML+OIL reasoning.

Ontologies are becoming widespread in many projects, like website management[2],
expert systems, and in agent-based environments like myCampus[3].  Having a
reasoner is crucial to fully utilizing knowledge from such ontologies.
An OWL reasoner will do everything a conventional DL reasoner[4] will do:
infer subsumption, role/range restrictions, equivalences, etc.

To answer the second part of your your question more specifically: one
will need an OWL reasoner whenever ontological knowledge is
used, which is going to be in many applications (like the above examples) as
Semantic Web technologies become more prominent.

Hope this helps,
-- 
Yarden Katz <[email protected]>  |  Mind the gap

[1] In web lingo, "properties"
[2] See <http://owl.mindswap.org>
[3] See <http://mycampus.sadehlab.cs.cmu.edu/>
[4] RACER is a robust conventional, non-opensource DL reasoner.  It is
tableaux-based and has support for DAML+OIL.  See
<http://www.cs.concordia.ca/~faculty/haarslev/racer/>