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Re: Question regarding open vs closed formulas (n3)

From: Seth Ladd <seth@brivo.net>
Date: 26 Jun 2003 16:54:27 -0400
To: Jeff Heflin <heflin@cse.lehigh.edu>
Cc: www-rdf-rules@w3.org
Message-Id: <1056660866.1597.219.camel@localhost>

On Thu, 2003-06-26 at 13:09, Jeff Heflin wrote:
> Seth,
> 
> I may have mispoke. According to [1]
> 
> > Originally, the name is from from "Closed World Machine" because it
> > processed information in a limited space, cwm does not make any
> > assumptions about a closed world.
> 
> In response, to the question about how can it ever return an answer
> without closing the formula, think of it this way. The tool returns all
> the answers it can compute, but there may be more it doesn't know about.
> It would only be a closed world if you then asked the negation of the
> query, and got back all of the other objects (i.e., it assumed if you
> don't know something is true, then it must be false)

I'm still not sold on how an open world can ever return all the answers
it can compute.  Unless it specifically understood that what it is
trying to return is an open set of answers.  If that is true, then the
formula is only making a best guess for answers (as far as the eye can
see?).

I'd like the same type of freedom in my rules.  I'd like to say, given
all these facts that I can see, create a List.  Yes, it's closed, but I
have every right to create a closed List as I do create any triple as
the result of some other facts.  There's no obligation to prove any of
those triples are truly true.

I wonder if I can argue if anything/anyone anywhere can truly know
something is a closed List.  In an open world, how can something be
closed?  Unless it's closed based on only what the observer can
observe.  Which, if that's true, means I should be able to write rules
that convert a list of facts into a List.

Ideas?

Thanks!
Seth
Received on Thursday, 26 June 2003 16:54:33 UTC

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