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Re: Statements/Stating: a proposition

From: Bill de hÓra <dehora@acm.org>
Date: Thu, 21 Dec 2000 16:17:15 -0000
Message-ID: <014d01c06b6a$10fe98c0$e772883e@dehora>
To: "ML RDF-interest" <www-rdf-interest@w3c.org>
Hash: SHA1


: Consider a statement S which occurs in two documents,
: http://foo and http://bar.
: Let RS be a reified statement representing both S and
: its occurrence in http://foo.  Thus:
:    (occursIn, RS, http://foo)
: is true.

You opener is ambiguous. When you say "both S and its occurence",
does "its" refer to S or RS? If S then your ensuing statement might
be true iff RS is present with S in http://foo. If RS is present then
the ensuing statement is true. By "present" I mean
syntactically/literally present.

More ambiguity. What are the intended semantics of "occursIn" wrt to
a model of a statement? Does it mean syntactically/literally present,
or, does it mean can be inferred by the presence of the statement
being modelled, or, does it mean something else?

Also, I'm not altogether sure that RS can represent both S and its
occurence. Again this is ambiguous. Do you mean an occurence of S
within http://foo, or do you mean that RS stands for the statement S
and any occurence/instance of S?

A while back I posted a request that the RDFm clean up its language
wrt to refication in future versions, and I believe you were the only
one who followed up in agreement. And this is why: the simplest of
discussions on this matter become torturous otherwise. We've spent a
lot of time going round and round in this area which could have been
greatly reduced if we had less ambiguous terms to use.

: Is
:    (occursIn, RS, http://bar)
: true?

It might be true. But it might be false also. There isn't enough
information to determine one way or another.

: Is this a contradiction?

Probably not.

: I really don't understand why folks are so reluctant
: to accept that statements and their occurrences are
: two different concepts and need different resources
: to model them.  What is the big deal?

I don't know what you mean exactly by "occurrences" but I suspect
you're right.

- -Bill de hÓra

Version: PGP 7.0

Received on Thursday, 21 December 2000 11:23:35 UTC

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