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RE: LC reply drafted

From: Michael Schneider <schneid@fzi.de>
Date: Wed, 13 May 2009 08:34:45 +0200
Message-ID: <0EF30CAA69519C4CB91D01481AEA06A0013939B1@judith.fzi.de>
To: "Bijan Parsia" <bparsia@cs.manchester.ac.uk>, "Sebastian Rudolph" <rudolph@aifb.uni-karlsruhe.de>
Cc: "W3C OWL Working Group" <public-owl-wg@w3.org>
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/.


>-----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 06:35:25 UTC

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