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Re: A triple is not unique.

From: Seth Russell <seth@robustai.net>
Date: Sun, 19 Nov 2000 15:07:18 -0800
Message-ID: <3A185D26.A8451064@robustai.net>
To: "McBride, Brian" <bwm@hplb.hpl.hp.com>
CC: "'Jonas Liljegren'" <jonas@rit.se>, Dan Brickley <danbri@w3.org>, RDF-IG <www-rdf-interest@w3.org>
"McBride, Brian" wrote:

> For the record, section 5, the formal model section of M&S states:
>
>   There is a set called Statements, each element of which is a triple
>   of the form {pred, sub, obj}
>
> That says that each Statement is a triple of the form (s,p,o).  A
> triple in mathematics is uniquely determined by its three components.

Yes, but to what particular set of statements does section 5 refer?
Certainly that set cannot be  all possible instances of RDF triples ever
asserted, because that would not even be a set.  No, the only thing that
makes sense, is that the section 5 refers to a collection of triples which
subscribes to the axiom that multiple triples are not allowed.

> How can two identical things
> have different identity?

They can't.

> If they  have different identity, they are not
> identical!

True.

Therefore if we can distinguish between triples they are in different sets
(different models, different contexts, different semantic islands).  The
question remains how do we point them out from model to model.

> Different representations of statements.  In my world model, statements
> are abstract and don't have a location on the net.  Perhaps yours is
> different.

Yep.  There certainly will be semantic islands which share your assumption;
but I don't think we want to legislate that assumption in RDF.

Seth Russell
Received on Sunday, 19 November 2000 18:06:03 GMT

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