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Re: model theory of error

From: Michael Kifer <kifer@cs.sunysb.edu>
Date: Thu, 10 Jan 2008 15:45:29 -0500
To: Christian de Sainte Marie <csma@ilog.fr>
Cc: RIF WG <public-rif-wg@w3.org>
Message-ID: <32590.1199997929@cs.sunysb.edu>


You may have noticed that I am trying to keep you away from your dinners
for several days now.  It is part of my tactic for wearing you down :-)

> Michael Kifer wrote:
> > 
> > [...]  As is, the
> > above paragraph is not a model theory but a model-theoretic gobbledeegook.
> > If you can turn it into something formal - fine. If not, let's not waste
> > time.
> 
> I do not think that I said that it was a model theory. Actually, what I 
> am trying to say from the beginning is that we should consider _not_ 
> giving it a model theory.
> 
> I tried to say it on every tune I could imagine and I used that specific 
> sentence because when Bijan used it you did not reply that it was mud, 
> gobbledeegook or hand-waiving, so I thought that it made sense to you :-)
> 
> So, let me attempt a final try, and then I abandon...
> 
> I do not propose that we abandon specifying a model-theroretic semantics 
> to BLD: I propose that we keep the undefined part of evaluated functions 
> and predicates out of BLD. In fact, I do not even propose that: I only 
> propose that we consider that option!

What I was trying to explain is that if we give a model theory then we
cannot "keep the undefined part of evaluated functions and predicates out
of BLD." We can either give a complete semantics (options (a) or (b), if
(b) works out) or we can keep the builtins completely out of the model
theory and pretend that we did not notice the problem (option (0) in my
earlier email).

In my view, option (0) is unsatisfactory because it basically does not define
what rule exchange means in the presence of builtins.

Options (a) and (b) are also unsatisfactory, although to a lesser extent.
Note that, Bijan pointed out that option (b) is not superior to (a), even
if we knew that (b) works. This is because OWL uses option (a), so
exchanging SWRL through RIF (with option (b)) would mean that SWRL systems
will not be able to use RIF builtins for exchange, if they want to be 100%
semantically correct.


	--michael  

> >>I understand that alternative (c) would not work if we were chartered to 
> >>specify a rule language, but that is one of the benefits of having to 
> >>specify "only" an interchange format that it works for us!
> > 
> > What do you mean by "works for us"? Who is "us".
> 
> In that specific sentence, "us" stands for the RIF WG as it is chartered.
> 
> And now, for me, it is off to diner and sleep :-)
> 
> Christian
> 
> 
Received on Thursday, 10 January 2008 20:45:36 GMT

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