W3C home > Mailing lists > Public > www-rdf-logic@w3.org > February 2002

Re: Reification thing questions

From: Seth Russell <seth@robustai.net>
Date: Tue, 5 Feb 2002 12:06:37 -0800
Message-ID: <024a01c1ae80$9e71f580$657ba8c0@c1457248a.sttls1.wa.home.com>
To: "Patrick Stickler" <patrick.stickler@nokia.com>, "Pat Hayes" <phayes@ai.uwf.edu>
Cc: "RDF Logic" <www-rdf-logic@w3.org>
From: "Patrick Stickler" <patrick.stickler@nokia.com>

> >>>>> For example:
> >>>>> foo:bar goo:dar poo:sar.
> >>>>> [
> >>>>> rdf:type rdf:Statement;
> >>>>> rdf:subject foo:bar;
> >>>>> rdf:predicate goo:gar;
> >>>>> rdf:object: poo:sar;
> >>>>> ex:time "9:15PM"
> >>>>> email::mid  0$657ba8c0@c1457248a.sttls1.wa.home.com ;
> >>>>> ex:documentLocation  :SethsOutbox
> >>>>> ]

> There is only one triple, and it is abstract. It is
> simply the combination of three values for S, P, and O.


> Triples/statements may be expressed in various contexts, or
> have different provenence, such that different reification
> bNodes may have different additional properties to
> subject, predicate, and object. But it's all the same
> triple. It's all the same knowledge.

I misstated above buy just saying 'the triple in my outbox', I should have
said 'the occurrence of the triple in my outbox'.

> So when you say that the copy of the reified statement
> describes the same triple, that is in the original document,
> that doesn't seem quite right.

Yes it wasn't quit right.   The reification node of rdf:type rdf:Statement
that appears even now in whatever copy of this email refers to the
*occurrence* of *the* triple in my outbox, and not the triple itself which
exists in Plato's Heaven.   Now does it make sense?

>The reification describes some
> assertion of that triple within the context of your document
> at a given point in time, but the triple itself was
> not and is not in the document. It's nowhere. It's everywhere.

Right, there are a lot of terms for this floating around ... let me list the
ones I have seen:
- occurrence of a triple
- sighting of a triple
- statement
- assertion of a triple
Perhaps we should decide on one term and stick with it.

Incidentally I have made a mentograph, perhaps you saw it, that clearly
depicts the 4 things involved and even suggests a formula for the MT:


The formula being:
k( i(?y)) = j(l(?y))
You'll need to look at the diagram to read off the terms.  I'm new at
groking these kinds of formula so I hope I got it right.  Did I?

>I need to go to bed.....  ;-)

You have done a good day's work indeed!

Seth Russell
Received on Tuesday, 5 February 2002 15:10:19 UTC

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