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Re: RDF vocabulary definitions

From: Richard H. McCullough <rhm@cdepot.net>
Date: Thu, 21 Nov 2002 15:29:48 -0800
Message-ID: <004401c291b5$e2453650$bd7ba8c0@rhm8200>
To: <www-rdf-interest@w3.org>, "David Menendez" <zednenem@psualum.com>, "Brian McBride" <bwm@hplb.hpl.hp.com>
Some food for thought concerning recent discussions:

1. re: replacing text by text I know to be wrong 
I certainly don't advocate that, but we could make it right -- in the following sense.
The classes that were illustrated are a hierarchy.
If you implement the other changes in RDFS semantics which I have recommended,
including proper subsets and 2. below, I think you will get a lattice  -- with no loops.
If you group the "extra" properties according to the classification criterion used,
you will get a different hierarchy for each classification criterion (each context).

2. re: RDF schema classes are members of the class rdfs:Class
I still think that produces contradictions.  I think you have to say
    RDF schema class names are members of the class rdfs:Class

3. "metaclass" was strictly off the top of my head
"meta" has been used as an attribute of anything that refers to statements.  
I'm sure "reified" has been used more often in the RDF community,
but in the world at large I think "meta" is used more.
============ 
Dick McCullough 
knowledge := man do identify od existent done
knowledge haspart list of proposition

  ----- Original Message ----- 
  From: Brian McBride 
  To: Richard H. McCullough ; www-rdf-interest@w3.org ; David Menendez 
  Sent: Thursday, November 21, 2002 1:12 PM
  Subject: Re: RDF vocabulary definitions


  At 11:17 21/11/2002 -0800, Richard H. McCullough wrote:
  >Brian
  >My comments are in the attached file, mcbride.txt

  Richard,

  The first line of your suggested replacement takes the original:

     [[Resources may be divided into groups called classes]]

  and replaces it with

     [[Resources may be divided into hierarchical groups called classes.]]

  You then note that its not really a hierarchy, its a lattice.  Which is 
  also wrong by the way.  There can be loops.

  I'm afraid that suggesting replacement text which is just wrong, and you 
  know to be wrong, isn't all that helpful.  Nor are the references to terms 
  such as metaclasses, contexts, class names etc which are simply not part of 
  RDFS .

  Please bear in mind that we are trying to describe RDFS here, not something 
  else you may have in mind.

  You have picked up an point that might be better expressed, for which thanks:

     [[The group of resources that are RDF Schema classes is itself a class 
  called
  rdfs:Class.]]

  might better be

     [[RDF schema classes are members of the class rdfs:Class.]]

  You have stated that:

    [[ll classes are subclasses of themselves.
  <<this is true, but RDF Schema should use proper subsets instead of subsets.
  Using subsets logically permits such absurdities as: the set of all men is
  identical to the set of all animals.>>]]

  I'm intrigued by that one.  We have a major flaw if that is true.  Care to 
  explain?

  Brian
Received on Thursday, 21 November 2002 18:29:49 GMT

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