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Re: Notes on updates to RDF Schema

From: Frank Manola <fmanola@mitre.org>
Date: Thu, 31 Oct 2002 08:53:48 -0500
Message-ID: <3DC135EC.1060301@mitre.org>
To: Patrick Stickler <patrick.stickler@nokia.com>
CC: ext pat hayes <phayes@ai.uwf.edu>, ext Brian McBride <bwm@hplb.hpl.hp.com>, w3c-rdfcore-wg@w3.org

The RDF normative specs may or may not define literals as resources, but 
if they do, they better not do it by saying:

 >>>
 >>>   rdfs:Literal rdfs:subClassOf rdfs:Resource .
 >>>

because classes (including Literal and Resource) and subclasses are not 
defined in RDF, they are defined in RDFS (note the namespace prefix). 
M&S said literals and resources were disjoint, but didn't do it using 
declarations involving classes.  We're either going to keep these 
languages separate, or we're not, and either way, we need to be consistent.

--Frank


Patrick Stickler wrote:

> 
> 
> [Patrick Stickler, Nokia/Finland, (+358 40) 801 9690, patrick.stickler@nokia.com]
> 
> 
> ----- Original Message ----- 
> From: "ext Brian McBride" <bwm@hplb.hpl.hp.com>
> To: "Patrick Stickler" <patrick.stickler@nokia.com>; "ext pat hayes" <phayes@ai.uwf.edu>
> Cc: <w3c-rdfcore-wg@w3.org>
> Sent: 31 October, 2002 11:36
> Subject: Re: Notes on updates to RDF Schema
> 
> 
> 
>>At 10:05 31/10/2002 +0200, Patrick Stickler wrote:
>>
>>[...]
>>
>>
>>
>>>If literals are resources, then the RDF normative specs should define
>>>
>>>   rdfs:Literal rdfs:subClassOf rdfs:Resource .
>>>
>>>If the normative specs do not define that, then I will rightly
>>>conclude that literals are not resources.
>>>
>>I'm not sure you can conclude that.  All you can really conclude is that 
>>you don't know whether they are or not.
>>
> 
> Well, since the specs are going to be defining a rather static
> ontology, it's unlikely that my system is going to encounter
> statements about the core RDF vocabulary that would be authoritative,
> in fact, for system integrity issues, I may rightfully choose to
> ignore any statements which extend the semantics of the core
> RDF vocabulary which are not explicitly and already defined by
> the specifications.
> 
> So, yes, in fact I do think it is quite reasonable to conclude that
> literals are not resources, if the RDF specs don't explicitly say
> they are.
> 
> Patrick
> 
> 
> 


-- 
Frank Manola                   The MITRE Corporation
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mailto:fmanola@mitre.org       voice: 781-271-8147   FAX: 781-271-875
Received on Thursday, 31 October 2002 08:41:23 EST

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