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Re: Using rdf reification to nest statements in N3 like contexts

From: Seth Russell <seth@robustai.net>
Date: Sat, 16 Mar 2002 08:06:56 -0800
Message-ID: <001101c1cd04$9aebea40$657ba8c0@c1457248a.sttls1.wa.home.com>
To: "Graham Klyne" <GK@NineByNine.org>
Cc: "RDFIG" <www-rdf-interest@w3.org>
From: "Graham Klyne" <GK@NineByNine.org>
To: "Seth Russell" <seth@robustai.net>
Cc: "RDFIG" <www-rdf-interest@w3.org>
Sent: Friday, March 15, 2002 2:23 PM
Subject: Re: Using rdf reification to nest statements in N3 like contexts


> At 12:28 PM 3/15/02 -0800, Seth Russell wrote:
> >From: "Graham Klyne" <GK@NineByNine.org>
> >
> > > Example:
> > >    A says { B says {C says D} . B a liar } .
> > > If I decide that what A says is true, I may enter the context of
> > > what A says and assert:
> > >    B says {C says D} . B a liar .
> > > If we have a syntactic construct for containment, as N3, then the
contents
> > > of {...} can be treated opaquely as you suggest.  But when all this is
> > > encoded into a flat space of triples, some other mechanism is needed.
I
> >am
> > > proposing (multiple levels of) encoding as reification-quads.
> >
> >Well I think that coding a triple as the RDF reification quad makes it
> >default to being opaque (not necessarialy true) in every context ... in
> >other words a reified statement is simply not asserted in any context.
>
> Yes.
>
> >   If we want the statement to be true in some context we will need to
> > invent a
> >property that asserts in that context.
>
> I was presuming a very general technique:  one "enters" a context by
> performing one level of "unreification" -- create a new graph with each
> rdf:Statement resource in the context generating a statement (triple)
> containing the corresponding subject, object and property.  Using my
> scheme, inner nested contexts still appear as reification quads.  The top
> level statements of the context entered come out as (non-reified)
> statements, hence asserted.

Well I don't see how this works in any practical manner because  you could
only access a particular context via the expression tree in which it was
entered.  How could you say arbritrary things about arbritray context nodes
?

... anyway did I get the mentograph of your proposal right?  The ded arc
from C to the inner nested context labeled with the Bnode _:4 would, imho,
not show up correctly.

http://robustai.net/mentography/context_n3_rdf_liar_comparison1.gif

Seth Russell
Received on Saturday, 16 March 2002 11:10:54 GMT

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