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Re: summary of 'a triple is not unique' and 'statements/reified' statements

From: Seth Russell <seth@robustai.net>
Date: Wed, 29 Nov 2000 08:35:41 -0800
Message-ID: <3A25305D.EF26A8BB@robustai.net>
To: Libby Miller <Libby.Miller@bristol.ac.uk>
CC: www-rdf-interest@w3c.org
Libby Miller wrote:

> Your suggestion begs the questions, what is a model? and what do you
> mean by 'imply a triple for it'?
> It seems to me that the recent thread on rdf-logic and rdf-interest
> implies that what a model isn't is a proper container for statements,

Well whatever else it is, or isn't, I'll bet we can form a consensus that a model
must at least contain statements.  Then all we need do, is wrangle out which
specific statements those are.  If you include the schema statements in the model,
and those schema statements can imply other virtual statements, i am happy to say
that the implied statements are "in the model" in just the same right as their
more tangible cousins.  But others will probably demur from that position ... and
in the long run it probably doesn't really matter .. just as long as we know to
who's kind of model we refer.

> Looking at your definition of when a model contains, a reification of a
> statement exists independantly to the statement itself, according to the
> M&S, so that contains(s,p,o) would be false if the interpretation of the
> model only contains a reification of the statement. So because of our
> reinterpretation of the statements we've found from a rdf source, we get
> different query results than if we had not reified the statements.

Well, If I understand you correctly,  I think you have put your finger on
something;  and it is precisely the point where I disagree with Graham's
definition of what context is.   He says  "context is a collection of ~reified~
statements"; I say "context is a collection of statements".    So the statement
[id1, s1, p1, o1] can be in the collection, and any statement about that statement
[id2, s2, p2, id1] may also, independently, be in that same collection (or not) ..
or any other collection for that matter in which it belongs.  So when we  browse
our attention to a particular context, the statements in that context show up
...that is [contains (idX, sS, pX, oX)] becomes true.  I mean, what you say about
what I say, certainly is not necessarily in the same context as what I say, or
even what I mean.

> and that we do need something like Gabe's suggestion of bags of reified
> statements [1] at least as an interpretation of the information from a
> source of RDF (I don't think Gabe means that all serializations of RDF
> should follow this format, just the handling of rdf data from other
> sources - I might be wrong...). So this has implications for handling
> the triples we have in a consistent way from different sources, and
> therefore also implications about how we match triples (as in your
> suggestion) and by extension, for querying.

I must be getting old, I simply cannot follow what Gabe is saying.  It seems to
conflate the syntax and  the model in a way that I am not used to.  I keep
worrying that I am being tricked, and I won't be able to put a statement in a
context, and then put statements about those statements in another context.
Perhaps this has been provided for, but I haven't seen any diagrams that I
understand.  Sorry, If I can't see it in a diagram, then I don't believe it.

Seth Russell
Received on Wednesday, 29 November 2000 11:33:12 UTC

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