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Re: Imports issue

From: Sean Bechhofer <seanb@cs.man.ac.uk>
Date: Thu, 20 Feb 2003 09:27:22 +0000 (GMT Standard Time)
To: Dan Connolly <connolly@w3.org>
cc: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>, Guus Schreiber <schreiber@swi.psy.uva.nl>, <www-webont-wg@w3.org>
Message-ID: <Pine.WNT.4.44.0302200909540.2400-100000@potato>

On Wed, 19 Feb 2003, Dan Connolly wrote:

>
> On Wed, 2003-02-19 at 18:40, Peter F. Patel-Schneider wrote:
> > From: Guus Schreiber <schreiber@swi.psy.uva.nl>
> > Subject: IImports issue
> > Date: Thu, 20 Feb 2003 00:26:57 +0100
> >
> > > I'm feeling increasingly uncomfortable about our "imports" resolution
> > > (see the discussion threads cited in the agenda).
> > >
> > > Unless we get in the very near future clear evidence this is an
> > > implementable language feature, I will have to reopen this issue and
> > > propose to give imports the same informnal status as the versioning stuff.
> >
> > Huh?
> >
> > To implement imports, it suffices to modify an RDF/XML processor as
> > follows:
> >
> >    Whenever an imports triple is found, first check to the if the object of
> >    the triple has been imported already.   If not, get the document that is
> >    pointed to by the object of the triple and run it through the RDF/XML
> >    processor.  Then merge the result with the current graph.  Only a very
> >    small amount of care is required to prevent loops.
> >
> > What could be easier?
>
> Then why aren't tools that do that widely deployed?
> Or at least available to this WG in some form?

Ok. I didn't really want to publicise this until it was finished as it is
still buggy and hasn't kept in step with the latest changes to the
vocabulary (annotion props etc). There are also a number of places where I
think my interpretation of the species rules are possibly wrong. And it
runs on my desktop machine :-).

http://potato.cs.man.ac.uk:8081/OWL/Validator

It is likely to be up and down periodically while we work on it. Once a
stable version is available I will advertise a further URL. Please don't
circulate widely at this point.

>
> > What is currently being argued about is how imports interacts with OWL Lite
> > and OWL DL, i.e., what documents containing imports count as an OWL Lite or
> > OWL DL document.
> >
> > > Note that responses of the type "this is a useful/necessary feature" are
> > > not helpful at this point.
> >
> > > If we cannot show that imports  can be
> > > implemented, we will not be able to go to Proposed Rec with the OWL spec
> > > as it stands.
> >
> > This is crazy!  Who has claimed that imports is not implementable!
>
> I have; that is: I have claimed that we do not have
> sufficient implementation experience to standardize
> it at this time.
>
> I suppose Sean B's code is implementation experience
> that's available to this WG, but note that his experience
> led him to propose to change the design.
>
> If there is no code to support the WG's claim that
> owl:imports is specified in an interoperable,
> workable, useful way, I don't see
> how we can expect The Director to uphold the WG's
> decision in spite of the outstanding dissent.

I would say here that it depends on what you want imports to be. If it is
a mechanism whereby you can pull in all the triples from some other
location (possibly following the transitive closure if necessary), then it
works (and is trivially implementable). This will certainly be useful for
some purposes.

	Sean

-- 
Sean Bechhofer
seanb@cs.man.ac.uk
http://www.cs.man.ac.uk/~seanb
Received on Thursday, 20 February 2003 04:28:45 GMT

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