W3C home > Mailing lists > Public > public-rif-wg@w3.org > March 2006

Re: [UCR] RIF needs different reasoning methods

From: Sandro Hawke <sandro@w3.org>
Date: Sun, 12 Mar 2006 18:21:23 -0500
To: "Gerd Wagner" <wagnerg@tu-cottbus.de>
Cc: public-rif-wg@w3.org
Message-Id: <20060312232124.593264F627@homer.w3.org>


> Sandro Hawke wrote:
> > To help keep us on track for Phase 1, the charter gives us a limit
> > (roughly Horn rules) on which features of each system we will cover.
> > Within that limit, I'm not sure there are many questions about which
> > systems to cover.
> 
> "Roughly Horn rules" seems to exclude 
> 
> - production rules (and ECA/reaction rules)

What about production rules where the only action is assert?  Are those
too different from Horn to count as "Roughly Horn" or are they just not
interesting enough to bother with.

> - nonmonotonic reasoning rules (for defaults and heuristics)
> 
> It seems to include:
> 
> - limited forms of constructive derivation rules (such as 
>   SQL views without negation)
> - limited forms of (normative) integrity rules/constraints 
>   (such as certain SQL ASSERTION clauses)

Right.

> Ian Horrocks wrote:
> > If the RIF supports rules with different meanings (i.e., 
> > where different behaviour of the consuming system is  
> > expected), then clearly 
> > they would need to be distinguished. I don't see anyone 
> > disagreeing about that.
> 
> OK, then we agree on Francois' proposal to mark/annotate
> the distinction between these different types of rules
> (I think this was the main point of the debate, and not 
> the issue of efficient proof theories).

I think the key question is to what extent we want to support different
types of semantics for rules with the same syntax.  Is that really a
good thing? 

    -- sandro
Received on Sunday, 12 March 2006 23:21:26 GMT

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