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Re: reification test case

From: Seth Russell <seth@robustai.net>
Date: Wed, 6 Feb 2002 10:27:42 -0800
Message-ID: <00d101c1af3b$f6f272a0$657ba8c0@c1457248a.sttls1.wa.home.com>
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
Cc: <www-rdf-logic@w3.org>
From: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>

> OK, but to completely fit in with M&S something like the following is
needed:
>
> 1/ There is exactly one triple with a given pred, sub, and obj,
>    so there can be at most one element of Statements with a given
>    pred, sub, and obj.
>
> 2/ For each triple, consisting of a given predicate, subject, and object,
>    there is at most one resource that is the sub of four elements of
>    Statements; one with pred rdf:type and obj rdf:Statement, one with pred
>    rdf:predicate and obj predicate, one with pred rdf:subject and obj
>    subject, and one with pred rdf:object and obj object.

Hmmm .. you seem intransigent on this point.  Good thing I'm not a member of
the WG, because I couldn't live with that.  .

> But why not use the current M&S stuff as it is?  If you want multiple
> ``reifications'', then why not use some other mechanism?

Which is a bigger change to M&S than the fix that people like me are calling
for.

> > <rdf:description>
> > <rdf:type>:Statement</rdf:type>
> > <rdf:subject>:Gore</rdf:subject>
> > <rdf:predicate>:wonThe</rdf:predicate>
> [ <rdf:object>:election</rdf:object> ]
> > <log:truthValue>False</log:truthValue>
> > </rdf:description>
> >
> > which holds for all such statings.
> >
> > But I could also write:
> >
> > <rdf:description>
> > <rdf:type>:Statement</rdf:type>
> > <rdf:subject>:Gore</rdf:subject>
> > <rdf:predicate>:wonThe</rdf:predicate>
> > <dc:author>:Seth</dc:author>
> > <log:truthValue>False</log:truthValue>
> > </rdf:description>
> >
> > which holds for a smaller collection of statings.
>
> HUH?  What is the difference here?  How do you distinguish between these
> two uses?  As far as I can see both resources have equivalent status as
far
> as RDF is concerned.

Did you miss the extra restraint <dc:author>:Seth</dc:author> in the latter
case ?

Do the following two nodes refer to the same thing or "have equivalent
status as far as RDF is concerned" ?

[a :Book; title "Knowledge Representation"; dc:author "John F. Sowa"]
[a :Book; title "Knowledge Representation"; dc:author "John F. Sowa";
:ownedBy "Seth Russell" ;sittingOn :MyDesk]

Seth Russell
Received on Wednesday, 6 February 2002 13:31:23 GMT

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