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Re: log:forSome (Was: Model-specific identity for anon resources, and its representation: A new issue?

From: Graham Klyne <Graham.Klyne@Baltimore.com>
Date: Tue, 26 Jun 2001 12:09:22 +0100
Message-Id: <5.0.2.1.2.20010626115944.0365ed20@joy.songbird.com>
To: jos.deroo.jd@belgium.agfa.com
Cc: phayes@ai.uwf.edu, w3c-rdfcore-wg@w3.org
It looks like a Description Logic "Least Common Subsumer" evaluation to me 
(see [1]).

#g
--

[1] Description Logics in Data Management
     Alexander Borgida
     IEEE Transactions on Knowledge and Data Engineering
     Vol. 7, No. 5, October 1995

Abstract:  http://computer.org/tkde/tk1995/k0671abs.htm
(Article text is linked from here, but requires IEEE CS digital library 
membership.)

Description logics and reasoners, which are descendants of the kl-one 
language, have been studied in depth in Artificial Intelligence. After a 
brief introduction, we survey in this paper their application to the 
problems of information management, using the framework of an abstract 
information server equipped with several operations -- each involving one 
or more languages. Specifically, we indicate how one can achieve enhanced 
access to data and knowledge by using descriptions in languages for schema 
design and integration, queries, answers, updates, rules, and constraints.

Index Terms-- Description, concept, terminological, language, subsumption, 
knowledge representation, object-oriented schema, intension
The author is with the Department of Computer Science, Rutgers University, 
New Brunswick, NJ 08903, USA. E-mail: borgida@cs.rutgers.edu.



At 06:20 PM 6/25/01 +0100, jos.deroo.jd@belgium.agfa.com wrote:


>[...]
> >>I agree that you CANT unify distinct existentially quantified
> >>variables in the sense that one does with universally
> >>quantified variables i.e. computing a MGU (Most General Unifier)
> >>but what we actually compute is a LCU (Least Common Unifier)
> >
> >Whoa!  Ive never heard that term before. Can you specify what you
> >mean? Eg give a sketch of this LCU algorithm, or some explanatory
> >examples?
>
>To make a sketch will take some time for me and
>to analyze the
>   final boolean unify(Euler t, Euler r, Stack s)
>method in the class
>   http://www.agfa.com/w3c/euler/Euler.java
>will take some time for you
>but examples are easier to find
>
>1.given the facts http://www.agfa.com/w3c/euler/danc.n3
>   then some query http://www.agfa.com/w3c/euler/danc-query.n3
>   produces result http://www.agfa.com/w3c/euler/danc-result.n3
>
>2.given the facts http://www.agfa.com/w3c/n3/ziv.n3
>   then some query http://www.agfa.com/w3c/n3/ziv-query.n3
>   produces result http://www.agfa.com/w3c/n3/ziv-result.n3
>
>3.given the facts http://www.agfa.com/w3c/euler/simulteq.axiom.n3
>   then some query http://www.agfa.com/w3c/euler/simulteq.lemma.n3
>   produces result http://www.agfa.com/w3c/euler/simulteq.proof.n3
>
>4.given the facts http://www.agfa.com/w3c/n3/rdfc25May.n3
>   then some query http://www.agfa.com/w3c/n3/rdfc25May.n3
>   produces result http://www.agfa.com/w3c/n3/rdfc25May-result.n3
>
>--
>Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/

------------------------------------------------------------
Graham Klyne                    Baltimore Technologies
Strategic Research              Content Security Group
<Graham.Klyne@Baltimore.com>    <http://www.mimesweeper.com>
                                 <http://www.baltimore.com>
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Received on Tuesday, 26 June 2001 07:16:08 EDT

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