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

RE: [UCR] RIF needs different reasoning methods

From: Gerd Wagner <wagnerg@tu-cottbus.de>
Date: Mon, 13 Mar 2006 00:41:11 +0100
To: "'Sandro Hawke'" <sandro@w3.org>
Cc: <public-rif-wg@w3.org>
Message-ID: <002901c6462e$71bdc560$17d52b8d@TMGWAGNER>

> 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.

They are too limited to be of an use. For instance,
while a virtual view (in a database) could be defined
with the help of a "Horn derivation rule", the
corresponding materialized view could not be defined
with a corresponding "Horn production rule" (because
keeping the materialzed view up-to-date would require 
a complementary retraction rule).

But this question should really be answered by our
production rule experts from ILOG and Fair Isaac.

> > 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? 

Are you asking if it's really a good thing to support
both derivation rules and integrity rules/constraints?
(These two types of rules are distinguished both in SQL
and in OCL.) 

Received on Sunday, 12 March 2006 23:44:27 UTC

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