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Re: Why do you want to do that?

From: Richard H. McCullough <rhm@pioneerca.com>
Date: Mon, 11 Aug 2008 22:56:16 -0700
Message-ID: <A6EEF2352E204BEB918BF444D9ED2BCD@rhm8200>
To: "Frank Manola" <fmanola@acm.org>
Cc: "Pat Hayes" <phayes@ihmc.us>, "Adam Pease" <adampease@earthlink.net>, "Semantic Web at W3C" <semantic-web@w3.org>, "KR-language" <KR-language@YahooGroups.com>

I finally got a few minutes to read OWL Guide 3.1.3
I read that section as supporting my position.  The word "context" is 
several times, with the implication that X ismem IndividualSet; in one 
and X ismem ClassSet; in a different context.

But a problem arises because OWL doesn't have contexts.
So, apparently, the OWL solution to mix all contexts together,
and ASSUME that all the propositions are still true.

To make this problem more apparent, we can specify the contexts

    at view =  ind { X ismem IndividualSet; };
    at view = cls { X ismem ClassSet; };

The question is: what happens when we mix the two contexts together?

Pat Hayes says
    at view = mix { X ismem IndividualSet; X ismem ClassSet; };
Dick McCullough says
    at view = mix { not{X ismem IndividualSet;}; X ismem ClassSet; };

Dick McCullough
Ayn Rand do speak od mKR done;
mKE do enhance od Real Intelligence done;
knowledge := man do identify od existent done;
knowledge haspart proposition list;

----- Original Message ----- 
From: "Frank Manola" <fmanola@acm.org>
To: "Richard H. McCullough" <rhm@pioneerca.com>
Sent: Friday, August 08, 2008 9:01 AM
Subject: Re: Why do you want to do that?

> On Aug 8, 2008, at 11:21 AM, Richard H. McCullough wrote:
>> Over the last six years, I have suggested a number of
>> "improvements" to the RDF language.  Not one of
>> my suggestions was adopted.  Apparently,
>> RDF is fine just the way is, thank you!
> Yep.  That doesn't imply opposition to improvements though;  some  people 
> think the way to provide the "improvements" they want is to  define 
> languages "on top of" RDF (like the OWL dialects) rather than  making 
> those changes directly in RDF.  That way, your "improvement"  and my 
> improvement can possibly co-exist more nicely :-)
>> I would now like to turn the tables, and ask
>> why do you want to do that?
>> I'll start with two features of RDF which seem to be popular.
>> 1. X  subClassOf  X;
>> A neat mathematical property, right?
>> But if you do the inferences, what it means is
>>   X  sameAs  X;
>> We already knew that.
>> Why do you want to do that?
> I need some help with this question.  Do you think being able to say X 
> subClassOf Y is OK?  If so, are you asking why RDFS (not RDF, BTW) 
> doesn't explicitly forbid the special case of X subClassOf X?  Why do  you 
> want to do that (i.e., test for this special case all the time)?   Or are 
> you asking why people *write* X subClassOf X?
>> 2. X  type  Y;  X  subClassOf  Z;
>> Another neat property: X is an individual and a class.
>> Now I can ... What?  I don't know.
>> Why do you want to do that?
> How about the example in Section 3.1.3 of the OWL Guide?
> --Frank
Received on Tuesday, 12 August 2008 06:00:00 UTC

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