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Re: [RIF] Extensible Design

From: Michael Kifer <kifer@cs.sunysb.edu>
Date: Thu, 04 May 2006 11:51:01 -0400
To: "Peter F. Patel-Schneider" <pfps@inf.unibz.it>
Cc: hak@ilog.com, public-rif-wg@w3.org
Message-ID: <22299.1146757861@kiferserv.kiferhome.com>


"Peter F. Patel-Schneider" <pfps@inf.unibz.it> wrote:
>
> SEMANTICS
> 
> None.

????

We seem to be talking at cross purposes.

1. Our proposal was NOT a RIF. It was a concrete working proposal for starting 
   the development of RIF.

2. It covered only a subset, which we believe can be shared
   syntactically and semantically among RIF dialects.
   In particular, it didn't have a notion of a rule.
   (The part of your message, which I deleted, implied that it did.)

3. We explained clearly that the semantics of the dialects in which this
   condition language is embedded will be based on intended models.
   This is general enough to accommodate all of LP and much of FOL.
   PRs and active rules can also probably be fit in there with some work.
   What we called "semantics" in our proposal was carefully limited to the
   notion of satisfaction of a formula in a given interpretation -- it was
   NOT a semantics for a rule language, but a necessary component of any
   model-theoretic semantics.

4. RIF is not going to be based on a single logic/semantics. If you think
   it will then, I believe, you are in a small minority. We envision a
   taxonomy of dialects that have their own semantics where some dialects
   will extend others syntactically and semantically.

5. Given (4), your statement above is meaningless. There are well-known LP
   languages, which will serve as candidates for some of the RIF dialects,
   for which semantics is well defined (various languages that are based on
   the two most popular LP semantics).  The semantic part of our proposal
   abstracts the common part of all the semantics of all these dialects, 
   and it is compatible with them.

   There is a question of how this might fit with languages for which
   semantics is not sufficiently formalized or well accepted. For instance,
   production and reaction rules. There is also a question of how much it is
   compatible with the FOL semantics of DLs. So, there is work to do for
   the working group, but this is a start.

6. We are trying to find a coherent way to unify the various dialects that
   are of interest to this WG. It was clearly the purpose of the roadmap
   that Harold presented at the F2F2, of my talk at the F2F, and of the
   document in question.
   
   As far as I could see from your presentation at the F2F2 and subsequent
   discussions, your idea is to take your FOL-based SWRL language and only
   tweak it a little. I don't believe that this will be acceptable to this
   WG.


	--michael  
Received on Thursday, 4 May 2006 15:51:17 GMT

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