W3C home > Mailing lists > Public > www-rdf-comments@w3.org > July to September 2002

Re: rdfs:subClassOf and metaclasses

From: Brian McBride <bwm@hplb.hpl.hp.com>
Date: Mon, 01 Jul 2002 19:05:45 +0100
Message-Id: <5.1.0.14.0.20020701190211.04ff1e90@15.144.25.13>
To: Piotr Kaminski <piotr@ideanest.com>, www-rdf-comments@w3.org, dan Brickley <danbri@w3.org>, Guha <guha@alpiri.com>

At 10:41 01/07/2002 -0700, Piotr Kaminski wrote:
[...]

>I see (at least) 3 possible answers:
>
>1.  That's your problem, not RDFS'.

I think that's the answer.  RDFS has no notion of meta class.  You are 
building that.

>   If you put enough constraints on the M2
>metaclasses, any M1 class that tries to be an instance of some unrelated
>bunch of them won't be able to have any M0 instances anyway.
>
>2.  You shouldn't use rdfs:subClassOf for subclasses of rdfs:Class.

I've done this and found it useful in a real application.  The classes I 
defined were not metaclasses, I just wanted to restrict the range (or 
domain, I can't remember) to one of a set of classes.

>Introduce your own subproperty of it, and restrict it to pairs of matching
>metaclasses.
>
>3.  Introduce a rule into RDFS prohibiting the situation above:

My take is that this going beyond what RDFS is trying to do.  Others may 
disagree.  Danbri, Guha?

Brian
Received on Monday, 1 July 2002 14:06:58 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Friday, 21 September 2012 14:16:30 GMT