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Re: Issue #danc-04 add a triviallyTrue predicate

From: Jos De_Roo <jos.deroo@agfa.com>
Date: Fri, 25 Apr 2003 23:01:04 +0200
To: "pat hayes <phayes" <phayes@ai.uwf.edu>
Cc: connolly@w3.org, Dan Brickley <danbri@w3.org>, www-rdf-comments@w3.org, www-rdf-comments-request@w3.org
Message-ID: <OF74F21EF5.65682F71-ONC1256D13.007267F7-C1256D13.00737622@agfa.be>


Pat, that works fine for me and I did some tests.
Having
{:rdf0. ?P rdf:type rdf:TriviallyTrue} => {?S ?P ?O}.
and
:comment a rdf:TriviallyTrue.
entails
<mailto:phayes@ai.uwf.edu> :comment "email address of a clever guy".

Hmm... do we need to detect inconsistencies
when someone asserts
rdfs:subClassOf a rdf:TriviallyTrue.
or some such?

-- ,
Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/


                                                                                                                          
                    pat hayes                                                                                             
                    <phayes@ai.uwf.edu>         To:     Dan Brickley <danbri@w3.org>, connolly@w3.org                     
                    Sent by:                    cc:     www-rdf-comments@w3.org                                           
                    www-rdf-comments-requ       Subject:     Re: Issue #danc-04 add a triviallyTrue predicate             
                    est@w3.org                                                                                            
                                                                                                                          
                                                                                                                          
                    2003-04-25 09:41 PM                                                                                   
                                                                                                                          
                                                                                                                          





>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.
>
>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
>>
>>(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?
>
>(in which case, trivially true seems to be a class of
>properties...?)

Good point. How about having TriviallyTrue be a class of properties?
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


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Received on Friday, 25 April 2003 17:01:21 GMT

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