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'weasel wording' was Re: Difference between syntactic building blocks and formal languages ...

From: Jonathan Borden <jborden@mediaone.net>
Date: Wed, 2 Jan 2002 12:40:28 -0500
Message-ID: <04ef01c193b4$91e0a6e0$0a2e249b@nemc.org>
To: <seth@robustai.net>, "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
Cc: <www-rdf-logic@w3.org>, <horrocks@cs.man.ac.uk>
Peter F. Patel-Schneider wrote:
> > Re:  http://lists.w3.org/Archives/Public/www-webont-wg/2001Dec/0173.html
> >
> > Quoting from: Ian Horrocks (horrocks@cs.man.ac.uk)
> >
> > [[
> > These sorts of problem illustrates just why we need a precisely
> > defined semantics for our languages. If we allow for two possible
> > interpretations we may get into all sorts of difficulties:
> >
> > - it may be impossible to say something in DAML+OIL without stating
> >   something unintended in RDF (and vice versa)
> >
> > - it may be impossible to know which of two (possibly conflicting)
> >   meanings is the intended one
> > ]]
> >
> > But if we consider RDF\triples to be just syntactic building blocks with
> > formal semantics whatsoever, then would we still have this problem?
> > view would mean that the entailments of any statement are only the
> > entailments that can be infered by the axioms related to the arc label.
> > other words property arcs have semantics and entailments, but languages
> > DMLS, RDFS don't.  This has the advantage of allowing us to mix and
> > all the available properties of all the schema written in or
> > into NTriples.
> RDF does have at least an intended meaning, and is probably getting a
> formal semantics.  In light of this, I feel that any use of RDF triples
> to conform with the intended meaning.
> > Would that work?  If not, why not?
> I think that the problem is what a web ontology language syntax would want
> to use the parts of RDF that have a non-trivial intended meaning which
> would get in the way.

Pat Hayes' formal semantics for RDF describes as "weasel worded" RDF triples
as "asserted" under common conditions. The weasel wording leaving the
specific possibility that collections of RDF triples (aka a 'graph') may
_not_ be asserted, rather useful in formulae. I think this possibility is
the single most important part of the RDF meaning, leaving open the real
possibility that a language (WOL) can itself define what collections of
triples are intended to be asserted and which are intended to be used to
construct a formula (i.e. the formula is itself asserted without asserting
each triple that it contains).

Thus, WOL can probably use/be compatible with RDF-MT in some fashion, though
it may not choose to employ the RDF syntax (which does not currently have a
representation for triples that are not members of the set of asserted

Perhaps it should be stated more explicitly in RDF-MT, get rid of the
"weasel wording" and call a statement a statement.

Received on Wednesday, 2 January 2002 12:41:57 UTC

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