W3C home > Mailing lists > Public > www-rdf-logic@w3.org > June 2001

Re: Why? Re: rdf as a base for other languages

From: Lynn Andrea Stein <lynn.stein@olin.edu>
Date: Fri, 01 Jun 2001 17:55:52 -0400
Message-ID: <3B180F68.9FEA001C@olin.edu>
To: Jonathan Borden <jborden@mediaone.net>
CC: www-rdf-logic@w3.org, Sandro Hawke <sandro@w3.org>


Jonathan Borden wrote:

> Sandro Hawke wrote:
> >
> > For example, here are 7 facts:
> >   1.  I can imagine a condition, X.
> >   2.  X can be expressed accurately as English sentence Y.
> >   3.  Y has four words.
> >   4.  The first word of Y is "the".
> >   5.  The second word of Y is "sun".
> >   6.  The third word of Y is "is".
> >   7.  The fourth word of Y is "shining".
> ...
> > Do you have any problem with this approach, beyond style?
>
> My problem with this approach is this:
>
> In order to decide the truth of any statement "X" I cannot simply test
> whether it is or is not a direct member of the set of Statements. If it is
> not a member, "X" might still be true, because it is inferred from the other
> statements as you describe.

This is essentially always true, unless you forbid inference and close the set
of sentences you're considering.  What's important is what we (minimally)
require that you be able to tell/infer and what we (maximally) permit you to
infer and what we do about any discrepancy that (almost inevitably) remains
between the two.

> So why say that statements are true just because they are members of this
> set? ...

> To me, stating that each statement in Statements is a fact does not gain me
> anything (in ease of inferencing) and costs me alot (of cumbersomeness and
> confusion).

Well, not "are true" and not "is a fact", but "is asserted by the document", at
least, which may be the same as far as your concern goes.  Certainly the
benefit (which is nonetheless present for some and in some applications) comes
at a cost (for those who buy into inference as a given).

I am under the impression that assertion by the document of statements
contained within the document is a fundamental tenet of RDF and there's no
changing it without dropping RDF. Assertion is *not* the same as truth of all
statements or documents, but it is certainly something one could question if
one were considering RDF or not RDF.  And I might take your approach in this
respect if I were building a language from scratch.

Lynn
Received on Friday, 1 June 2001 17:56:03 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:52:40 GMT