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Re: RDF MT: Default values for rdfs:domain and rdfs:range?

From: Jeen Broekstra <jeen.broekstra@aidministrator.nl>
Date: Thu, 28 Mar 2002 15:49:38 +0100
Message-ID: <3CA32D82.4020405@aidministrator.nl>
To: Brian McBride <bwm@hplb.hpl.hp.com>
CC: www-rdf-comments@w3.org

Hello Brian,

Brian McBride wrote:
 > At 14:27 28/03/2002 +0100, Jeen Broekstra wrote:
 >
 >> I am rather confused as to what exactly the domain/range of a
 >> property should default to if no explicit domain/range is
 >> specified,
 >
 > I don't think there is any notion of default.  In the absence of
 > domain/range constraints, then no constraints on the domain 
and range
 > are specified.
 >
 > Do you have a requirement for such defaults?

No, not really, and I am not even arguing in favor of adding such
defaults, I just wanted to know how other people interpreted
this. To be precise: I was wondering what the result of an RDF
query "give me the domain   of P" should be, given that P has no
domain specified.

[snip]

 > I think we have been deliberately vague about the relationship 
between
 > literals and resources.  We have some charter contraints that 
stop us
 > getting into this fully.  So we are leaving things as free as 
possible
 > for a future WG.  You might think of this as some deliberate
 > underspecification.

Fair enough.

 >> This leads me to think that the range of a property also defaults
 >> to rdfs:Resource, and that any use of that property with a
 >> literal value is within that range. Is this correct?
 >
 > You may care to assume that.  I couldn't possibly comment.
 > Sorry, English joke.  I won't say whether you are correct or 
not.  I
 > will say that RDF(S) makes no such statement.

I think this makes it sufficiently clear for me though: for the
time being, the answer to the query should be a variation of
"Sorry, no clue" :)

Thanks for your comments,

Jeen
-- 
jeen.broekstra@aidministrator.nl
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Received on Thursday, 28 March 2002 09:52:44 GMT

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