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Re: [Fwd: Negation and Disjunction in RIF]

From: Axel Polleres <axel.polleres@deri.org>
Date: Mon, 19 Nov 2007 12:49:07 +0000
Message-ID: <47418643.1090601@deri.org>
To: "Public-Rif-Wg (E-mail)" <public-rif-wg@w3.org>

I would suggest to answer the following:

Indeed, RIF's Basic Logic dialect (BLD) [1] does not support negation as
failure (NAF). Extensions of rule lanaugages by NAF and other variations
of negation (see [2]) are beyond phase 1 of RIF. The working group
however does at this point not preclude that we will already be starting
to work on dialects which include such extensions in parallel with
finishing Phase 1.

For instance, in the current proposal for a production rule dialect
(PRD), see [3], you will find a construct for negation as failure, which
is currently under discussion, i.e. this draft is not to be considered
as finalized.

Similar considerations apply for disjunction. Note that BLD allows
disjunction in rule bodies, but not in rule heads. Again, later dialects
and the generic extensibility mechanism we are currently working on
shall allow for such extensions.

with best regards,

1. http://www.w3.org/TR/2007/WD-rif-bld-20071030
2. http://www.w3.org/2005/rules/wg/wiki/negation
3. http://www.w3.org/2005/rules/wg/wiki/PRdialect


Christian de Sainte Marie wrote:
> All,
> The question below was asked on the rif-public-comments mailing list. 
> anyone cares to draft a reply?
> Christian
> ------------------------------------------------------------------------
> Subject:
> Negation and Disjunction in RIF
> From:
> "Pathak, Jyotishman, Ph.D." <Pathak.Jyotishman@mayo.edu>
> Date:
> Wed, 7 Nov 2007 09:52:40 -0600
> To:
> <public-rif-comments@w3.org>
> To:
> <public-rif-comments@w3.org>
> Hello everyone,
> I am a newcomer to this field and trying to learn. The question I have 
> is w.r.t. support for negation (specifically NAF: negation as failure) 
> and disjunction in RIF. As far as I know, SWRL natively does not support 
> them. Is this true for RIF as well?
> Thank you,
> - Jyoti

Dr. Axel Polleres
email: axel@polleres.net  url: http://www.polleres.net/
Received on Monday, 19 November 2007 12:49:35 UTC

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