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Re: LC reply drafted

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Wed, 13 May 2009 05:46:03 -0400 (EDT)
Message-Id: <20090513.054603.149880341.pfps@research.bell-labs.com>
To: schneid@fzi.de
Cc: bparsia@cs.manchester.ac.uk, rudolph@aifb.uni-karlsruhe.de, public-owl-wg@w3.org
Beyond the scope of the Primer.


From: "Michael Schneider" <schneid@fzi.de>
Subject: RE: LC reply drafted
Date: Wed, 13 May 2009 08:34:45 +0200

> And then, there is still also the RDF-Based Semantics, which interprets
> classes as /individuals/ that have a set of individuals /assigned/ to them
> as their class /extension/.
> Michael
>>-----Original Message-----
>>From: public-owl-wg-request@w3.org [mailto:public-owl-wg-request@w3.org]
>>On Behalf Of Bijan Parsia
>>Sent: Tuesday, May 12, 2009 9:54 PM
>>To: Sebastian Rudolph; W3C OWL Working Group
>>Subject: Re: LC reply drafted
>>On 12 May 2009, at 20:41, Sebastian Rudolph wrote:
>>> Dear all,
>>> if I interpreted the intention of the below LC comment correctly,
>>> Richard would like to see an explicit statement that classes just
>>> represent sets of individuals
>>But that would be to say something false. OWL Classes most obviously
>>do not "just" represent sets of individuals (as they can be mapped to
>>distinct sets in different interpretations). If anything, OWL Classes
>>are first order logic formulae with one free variable (and thus, when
>>atomic, correspond to monadic predicates).
>>> and that the notion of a "concept" is something related but different.
>>> I tried to address this by adding two sentences to the Primer
>>> document, see the diff at
>>""In modeling, classes are often used to denote the extension sets of
>>concepts of human thinking, like ''person'' or ''woman''."""
>>But this is precisely wrong:
>>	http://en.wikipedia.org/wiki/Definition#Intension_and_extension
>>(reductio ad wikipedia :)). So please don't use the word "extension".
>>The commentator has a strange idea of what a concept is (and of class,
>>and of set). I don't really want to import them into an already
>>tangled terminological situation.
>>> Find the proposed draft response at:
>>> http://www.w3.org/2007/OWL/wiki/LC2_Responses/RHM1
>>In general, readers of the primer aren't going to know what "extension
>>set" (er... generally known as the *extension*) is, so this wouldn't
>>be clarificatory even if it were right.
Received on Wednesday, 13 May 2009 09:45:36 UTC

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