W3C home > Mailing lists > Public > public-rif-wg@w3.org > April 2009

Re: AW: [Admin] Agenda for RIF telecon 28 April *ADDENDUM*

From: Sandro Hawke <sandro@w3.org>
Date: Tue, 28 Apr 2009 07:33:53 -0400
To: "Adrian Paschke" <adrian.paschke@gmx.de>
cc: "'Christian De Sainte Marie'" <csma@fr.ibm.com>, public-rif-wg@w3.org
Message-ID: <18801.1240918433@ubehebe>

> We discussed it in the last PRD telecon. The semantics of a generic
> "not" in case of PRD is clear since it used in a production rule set,
> i.e. it is inflationary not.

But is it also classical negation and NAF?  In particular, if I have
this ruleset:

   forall ?x
      if not ex:p(?x) then ex:q(?x)

this proposal defines that as a PRD ruleset.  To my eye, it could just
as easily be FOL or LPD.  As long as the semantics in all cases would be
the same, they could all use the same "not", but otherwise, it seems
like they need to use different operators.

> Alternative we could introduce many different constructs for
> negations, but this might be counterproductive to the interchange
> purpose of RIF. I would propose that the intended semantics of a rule
> set such as stratified, well-founded, stable models, is denoted by a
> special label (e.g. an attribute or additional construct) for the rule
> set and not by different constructs for negations. Otherwise a simple
> (business) rule set cannot be interchanged between a WFS rule engine
> and a Stable rule engine without a translation.

How would that work?  If a ruleset was labeled
"use-well-founded-semantics" and I was a "stable-semantics" engine, what
would I do with it?

     -- Sandro
Received on Tuesday, 28 April 2009 11:34:02 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 2 June 2009 18:34:05 GMT