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Re: [RIF-APS] Rules Sign

From: Michael Kifer <kifer@cs.sunysb.edu>
Date: Thu, 4 Sep 2008 12:48:02 -0400
To: "Hassan Ait-Kaci" <hak@ilog.com>
Cc: "Paul Vincent" <pvincent@tibco.com>, <public-rif-wg@w3.org>
Message-ID: <20080904124802.5140e247@kiferserv>

I completely agree.

michael

On Thu, 4 Sep 2008 08:24:15 -0700
"Hassan Ait-Kaci" <hak@ilog.com> wrote:

> Hello,
> 
> I don't know whether to feel alarmed or amused at the sort of
> symbol quibblings that have been exchanged regarding RIF PS syntax
> (dis)tastes.
> 
> I thought it was understood by all here that with a Presentation
> Syntax for rules, this WG was *not* designing a new universal
> rule language. We are simply defining shorthands that are
> somewhat easier to read and write by humans than their normative
> XML counterparts. The RIF PS is meant to help a human agent read
> and write RIF examples and allow the automated generation of the
> XML form from the PS form. Thus, such a PS should:
> 
>   (1) be simple and unambiguous to parse by software; and,
>   (2) easy, by not excessively so, to manipulate by humans.
> 
> Why "not excessively so"? Because - again - we are *not*
> designing a new universal rule language! We are just defining
> (relatively) less ugly shorthands for (absolutely)ugly XML! :-)
> Thus, PS is only rough syntax encompassing many potential rule
> languages. What makes sense for one intended sementics does not
> necessarily for another. AT this level, punctuation is important
> only to ease reading and parser generation. Let us not make it
> ridiculously peculiar. It should be clear and familiar to most.
> It is silly trying to push matters of personal (dis)tastes. The
> two criteria above are all we need.
> 
> At present, there are three levels of PS:
> 
> (1) "pure" PS (without Axel's extensions)
> (2) PS ("pure" PS with Axel's extensions)
> (3) APS (PS with Adrian's shorthands)
> 
> Adrian's abbreviations are more like macros that "desugar" APS
> into PS.
> 
> In order to build a parser for (A)PS and generate its XML form,
> [http://www.w3.org/2008/08/19-rif-minutes.html#action08], the
> quick final settlement of all these syntactic issues is highly
> desirable.
> 
> -hak
> 
> 
> -hak
> --
> Hassan Aït-Kaci  *  ILOG, Inc. - Product Division R&D
> http://koala.ilog.fr/wiki/bin/view/Main/HassanAitKaci
> 
> 
> 
> -----Original Message-----
> From: public-rif-wg-request@w3.org on behalf of Paul Vincent
> Sent: Thu 9/4/2008 2:51 PM
> To: public-rif-wg@w3.org
> Subject: RE: [RIF-APS] Rules Sign
>  
> +1 
> 
>  
> 
> '<= ' should be used in backward-chaining dialects, and '=>' in
> forward-chaining ones. 
> 
>  
> 
> Paul Vincent
> 
> TIBCO | Business Optimization | Business Rules & CEP
> 
>  
> 
> ________________________________
> 
> From: public-rif-wg-request@w3.org [mailto:public-rif-wg-request@w3.org]
> On Behalf Of Patrick Albert
> Sent: 04 September 2008 12:54
> To: Adrian Paschke; public-rif-wg@w3.org
> Subject: RE: [RIF-APS] Rules Sign
> 
>  
> 
> Most Production Rules system have rules in the form  IF/WHEN
> <conditions> THEN <actions>.
> 
>  
> 
> I'd recommend we adhere to the existing practice which is to have the
> conditions first followed by the actions. 
> 
> Replacing the IF .. THEN by a '=>' as in '<Conditions> => <Actions>'
> would be ok.
> 
>  
> 
>  Patrick. 
> 
>  
> 
> ________________________________
> 
> From: public-rif-wg-request@w3.org [mailto:public-rif-wg-request@w3.org]
> On Behalf Of Adrian Paschke
> Sent: lundi 1 septembre 2008 22:09
> To: public-rif-wg@w3.org
> Subject: [RIF-APS] Rules Sign
> 
>  
> 
> Hello,
> 
>  
> 
> With respect to the abridged presentation syntax there is still an open
> issue about the sign to distinguish the head and the body of a rule.
> 
>  
> 
> Currently, we use ":-" in the examples e.g. in UCR and PRD, which is
> well-known in the logic community but not so much in others including
> production rules.
> 
>  
> 
> I shortly discussed this issue with the BLD/FLD editors Michael and
> Harold and we came up with this unambiguous proposal to distinguish
> classical implication and rules head and body.
> 
>  
> 
> <== for PRD and BLD
> 
> <-- for classical
> 
>  
> 
> <== and <-- might be also reverted ==> -->
> 
>  
> 
> -Adrian
> 
>  
> 
>  
> 
>  
> 
> 
Received on Thursday, 4 September 2008 16:48:43 GMT

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