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

Re: Datatypes: the Bermuda Triangle, and how to fly over it.

From: Graham Klyne <Graham.Klyne@MIMEsweeper.com>
Date: Fri, 01 Feb 2002 14:23:39 +0000
Message-Id: <5.1.0.14.2.20020201142003.0389bec0@joy.songbird.com>
To: jos.deroo.jd@belgium.agfa.com
Cc: phayes@ai.uwf.edu, w3c-rdfcore-wg@w3.org, hendler@cs.umd.edu
At 02:28 PM 2/1/02 +0100, jos.deroo.jd@belgium.agfa.com wrote:
>GrahamK wrote:
> > I agree with your conclusion about the rdf:value+rdf:type idiom.
> >
> > I've been mulling a similar problem with some of my ideas, and I'm not sure
> > I'm convinced by the need to introduce anything new (rdf:dtype, or 
> whatever).
> >
> > Where there are multiple type constraints, why not simply require that they
> > *all* be satisfied, per conjunctive type semantics.  If the various applied
> > types cannot be simultaneously satisfied in this way then we simply have an
> > unsatisfiable graph.  Tough.
>
>well Graham, I think union is needed i.e. Pat's
>[[
>   BTW, the easiest way to understand rdf:value here would be that it is
>   a union (disjunction) of inverses of canonical submappings of the
>   datatype mappings in D, ie IEXT(I(rdf:value)) = {<x,y> : for some
>   datatype d in D, LV(d)(y)=x} .
>]]

I've yet to be convinced that union is needed.  I took Pat's proposal to 
mean that the rdf:type/rdf:value combination was treated as a distinct 
syntactic entity and as such I'm not concerned by the lack of an 
interpretation for rdf:value in isolation.

>we experimented with rdfd-theory.n3 i.e.
[...]
>and found no trouble (so far)

Sure.  I've no reason to believe it doesn't work... I just remain to be 
convinced that the extra typing property is needed.

#g


------------------------------------------------------------
Graham Klyne                    MIMEsweeper Group
Strategic Research              <http://www.mimesweeper.com>
<Graham.Klyne@MIMEsweeper.com>
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Received on Friday, 1 February 2002 09:24:19 EST

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