W3C home > Mailing lists > Public > w3c-rdfcore-wg@w3.org > February 2002

Re: the S-B problem and what to do about it.

From: Brian McBride <bwm@hplb.hpl.hp.com>
Date: Wed, 27 Feb 2002 16:38:00 +0000
Message-Id: <5.1.0.14.0.20020227161448.00b1ae98@0-mail-1.hpl.hp.com>
To: Pat Hayes <phayes@ai.uwf.edu>, w3c-rdfcore-wg@w3.org
Cc: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
At 14:54 24/02/2002 -0600, Pat Hayes wrote:

>At yesterdays telecon, by majority vote, we took two decisions about 
>datatyping which, if taken together, make RDF datatyping effectively 
>unusable by anyone except librarians. I cannot produce a coherent model 
>theory for datatyping which satisfies both of these conditions at the same 
>time, and would suggest that one of them should be reconsidered. This 
>message tries to briefly explain the problem, and suggest some alternative 
>ways out of it. I recommend option C below.
>
>The decisions were that (1) we should support the S-B idiom:
>
>Jenny ex:age "10" .
>ex:age rdfs:range xsd:integer .

There was no requirement in what we agreed that the range constraint 
property was rdfs:range or that value of the property was xsd:integer.
[...]

>The problem with this combination is that it seems to have the inevitable 
>consequence that the class named by a datatype name must be the set of 
>*lexical forms* of that datatype, rather than the value space of the datatype.

No.  What we decided leaves us free to use a different range property or 
xsd:integer.lex.
[...]

>Now, one option here would be to just smile at this - after all, we are 
>the RDF WG, not Webont - but I would suggest that if we are at all 
>interested in the possibility of RDF being acceptable as a foundation for 
>any more ambitious efforts, rather than an dead end, we should pay 
>attention to the likely needs of most people on the planet, who will want 
>to use numerals to refer to numbers, rather than treating the entire XML 
>datatyping scheme as a way of classifying character strings.

In my view, webont are a very important customer of our work.  When I took 
this on, I believed that the major challenge we faced is that RDF is trying 
to serve two masters, those who want a simple meta data language and those 
who want a formal foundation for it.  That's hard, but that is what we are 
trying to do.

At the very least we must not mess things up for webont to build on rdf.

Brian
Received on Thursday, 28 February 2002 01:53:54 EST

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