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Re: subject: ACTION 2001-09-21#5 subPropertyOf cycles

From: Frank Manola <fmanola@mitre.org>
Date: Thu, 27 Sep 2001 10:27:45 -0400
Message-ID: <3BB33761.D9A76A2B@mitre.org>
To: Graham Klyne <Graham.Klyne@mimesweeper.com>
CC: w3c-rdfcore-wg@w3.org
Graham Klyne wrote:
> 
> At 11:40 AM 9/25/01 -0400, Frank Manola wrote:
> >Here's the motion:  To resolve issue [?do we have an explicit issue?] by
> >deleting the restriction prohibiting cycles of subPropertyOf
> >properties.  The meaning of a cycle of subPropertyOf properties is an
> >assertion that the properties involved in the cycle have the same
> >members.  A more formal specification of the meaning is given in the
> >model theory.  [This has the same form as the explanation in the
> >"subClassOf" motion, but is less intuitive for properties.  I could
> >wordsmith this a bit, but it's probably safer to point to the model
> >theory].
> 
> I'm happy with the general intent.
> 
> Some nit-picking:

I agree:  this is nit-picking :-)

> 
> "...the properties involved in the cycle have the same members"
> Should this be:
> "... the [relational] extensions of properties involved in the cycle have
> the same members"
> ?

Your rewording is technically more correct;  it's just that we didn't
refer to the relational extension when we worded the corresponding
motion about class cycles (i.e., we didn't say "the relational
extensions of the classes").

> 
> "A more formal specification of the meaning is given in the model theory"
> I don't recall this point being explicitly addressed by the MT;  would it
> be more accurate to say "... given by the model theory"?

Fine with me.  Once again, the model theory doesn't talk explicitly
about class cycles either, if I remember correctly.  What it does do it
define what classes and properties (or rather, their extensions!) are
made up of.
Inferring what a cycle means is left as an exercise for the reader.

--Frank

-- 
Frank Manola                   The MITRE Corporation
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Received on Thursday, 27 September 2001 10:28:27 EDT

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