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RE: Reification quoting in RDF/N3 was: A note comparing Conceptu al Graphs and RDF/Semantic Web

From: Bill dehOra <BdehOra@interx.com>
Date: Thu, 18 Jan 2001 15:27:06 -0000
Message-ID: <23CF4BF2C499D411907E00508BDC95E131F87B@ntmews_01.interx.com>
To: "'Dan Brickley'" <danbri@w3.org>, "McBride, Brian" <bwm@hplb.hpl.hp.com>
Cc: Tim Berners-Lee <timbl@w3.org>, www-rdf-logic@w3.org


>>
This syntax problem bites hard when working with distrustful applications
that want to  use XML to exchange messages about various RDF claims. 
>>

You're chewed well before trust enters into it. I'm not sure we can claim
anything about a string literal. See below.

>>
Revisiting your example,
>>
>   <rdf:RDF>
>     <rdf:Statement>
>       <rdf:subject    rdf:about="mary"/>
>       <rdf:predicate  rdf:about="wants to marry"/>
>       <rdf:object     rdf:about="Fred"/>
>       <foo:believedBy rdf:about="John"/>
>     </rdf:Statement>
>   </rdf:RDF>

>>
Suppose we wanted to do this for real. 'Fred' is not a URI. Worse, Fred
doesn't have a URI name on the Web. Fortunately he is related to many
things that do. So lets go the route recently discussed of saying "let's
pick Fred out as an indivual through description; he is the Person whose
personalEmailbox is fred@example.com".
>>

Suppose we did want to do this for real. "Fred" is a string literal, not a
name, or even an alias for a person. These are commonsense assumptions about
what can be inferred out a string literal, that aren't neccessarily
available to a machine and machine understandability is what's at issue
here.  Consider:

<rdf:RDF>
     <rdf:Statement>
       <rdf:subject    rdf:about="mary"/>
       <rdf:predicate  rdf:about="wants to marry"/>
       <rdf:object     rdf:about="     "/>
       <foo:believedBy rdf:about="John"/>
     </rdf:Statement>
     <rdf:Statement>
       <rdf:subject    rdf:about="katie"/>
       <rdf:predicate  rdf:about="wants to marry"/>
       <rdf:object     rdf:about="     "/>
       <foo:believedBy rdf:about="John"/>
     </rdf:Statement>
     <rdf:Statement>
       <rdf:subject    rdf:about="     "/>
       <rdf:predicate  rdf:about="wants to marry"/>
       <rdf:object     rdf:about="     "/>
       <foo:believedBy rdf:about="John"/>
     </rdf:Statement>
</rdf:RDF>

Ignoring the predicates, how many unique entities are there for us to reason
about?

-Bill

----
Bill de hÓra  :  InterX  :  bdehora@interx.com
Received on Thursday, 18 January 2001 10:27:51 GMT

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