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Re: Issue #danc-04 add a triviallyTrue predicate

From: Dan Connolly <connolly@w3.org>
Date: 28 Apr 2003 10:41:25 -0500
To: Pat Hayes <phayes@ai.uwf.edu>
Cc: Dan Brickley <danbri@w3.org>, www-rdf-comments@w3.org
Message-Id: <1051544485.2632.925.camel@dirk.dm93.org>

On Fri, 2003-04-25 at 14:41, pat hayes wrote:
> >Dan,
> >
> >Could you explain in a bit more detail what you're asking for?
> >I'm having trouble understanding how an 'rdfs:triviallyTrue'
> >predicate might work.

You're thinking too hard, Danbri. It's just a predicate
where every possible statement using this predicate is true.


> >http://lists.w3.org/Archives/Public/www-rdf-comments/2003AprJun/0085.html
> >
> >>Consider adding to RDFS a triviallyTrue predicate;
> >>specification:
> >>
> >>    ?S rdfs:triviallyTrue ?O.
> >>
> >>is true for all ?S and ?O.
> >>
> >>Rationale:
> >>
> >>(1) jeremy's digital signature application needs
> >>to number bnodes

He seems to be content working with existing mechanisms.

> >>(2) folks are asking for all uses of rdfs:comment
> >>to be vacuously true. This would provide that
> >>functionality.
> >
> >In particular, I don't yet understand how this would relate to
> >the rdfs:comment concern. Is the idea that it should be
> >impossible to assert something false with an rdfs:comment
> >in the predicate role of a statement?

No, but to the folks who want that to be the case, we
tell them "don't use comment for that; use triviallyTrue".

perhaps rdfs:note would be a good name for it.
or rdfs:fyi.


> >(in which case, trivially true seems to be a class of
> >properties...?)
> 
> Good point. How about having TriviallyTrue be a class of properties? 

That's more complicated than what I'm asking for.



> Entailment:
> 
> ?P rdf:type rdf:TriviallyTrue .
> 
> |-
> 
> ?S ?P ?O .
> 
> ? The problem for Ian might be that this couldn't be an OWL-DL property.
> 
> But this is starting to seem kind of silly to me, to be honest.
> 
> Pat
-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Monday, 28 April 2003 11:41:08 GMT

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