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Re: RIF FAQ

From: Michael Kifer <kifer@cs.stonybrook.edu>
Date: Thu, 24 Jun 2010 13:02:10 -0400
To: Christian De Sainte Marie <csma@fr.ibm.com>
CC: public-rif-wg <public-rif-wg@w3.org>, Sandro Hawke <sandro@w3.org>
Message-ID: <20100624130210.58bec0c1@kiferserv>



On Thu, 24 Jun 2010 09:57:20 -0700
Christian De Sainte Marie <csma@fr.ibm.com> wrote:

> Hi Michael,
> 
> Hmmm...
> 
> Core: The mathematical English is normative, the EBNF is not normative; 
> both instances of the presentation syntax are not intended to be a 
> concrete syntax for RIF-Core. The English presentation syntax deliberately 
> leaves out details such as the delimiters of the various syntactic 
> components, escape symbols, parenthesizing, precedence of operators, and 
> the like. Since RIF is an interchange format, it uses XML, and only XML, 
> as its concrete syntax. 
> 
> BLD: In the non-normative subsection EBNF Grammar for the Presentation 
> Syntax of RIF-BLD, a grammar for a superset of the presentation syntax is 
> given using Extended Backus?Naur Form (EBNF). Neither the mathematical 
> English nor the EBNF is intended to be a concrete syntax for RIF-BLD. The 
> mathematical English deliberately leaves out details such as the 
> delimiters of the various syntactic components, escape symbols, 
> parenthesizing, precedence of operators, and the like. The EBNF does not 
> specify context-sensitive syntactic constraints. Since RIF is an 
> interchange format, it uses XML as the only concrete syntax, [...]
> 
> You may play with the words and say that the presentation syntax is, 
> really, the abstract one, or the mathematical english, or whatever; but I 
> guess that (almost) everybody, when speaking of the PS, will mean and 
> understand the one that is specified by the EBNF (what is a _presentation_ 
> syntax that is not a concrete syntax, anyway?).
> 
> So, we are both right :-)

Well, yes. We went through these arguments before. The presentation syntax is
an abstract syntax. EBNF is not normative only because it is context free and
BLD is not. So, you can't capture BLD in EBNF precisely. This is explained in
the intro to EBNF.

cheers
michael

> 
> Christian
> 
> IBM
> 9 rue de Verdun
> 94253 - Gentilly cedex - FRANCE
> Tel. +33 1 49 08 35 00
> Fax +33 1 49 08 35 10
> 
> 
> public-rif-wg-request@w3.org wrote on 24/06/2010 09:26:54:
> 
> > [image removed] 
> > 
> > Re: RIF FAQ
> > 
> > Michael Kifer 
> > 
> > to:
> > 
> > Christian De Sainte Marie
> > 
> > 24/06/2010 09:27
> > 
> > Sent by:
> > 
> > public-rif-wg-request@w3.org
> > 
> > Cc:
> > 
> > Sandro Hawke, public-rif-wg, public-rif-wg-request
> > 
> > Please respond to kifer
> > 
> > Christian,
> > you should familiarize yourself with the spec. :-)
> > 
> > The presentation syntax in Core and BLD is explicitly normative.
> > Only PRD says *its* presentation syntax is not normative.
> > This is a *bug,* but I will not try to dissuade you.
> > 
> > michael
> > 
> > 
> > On Thu, 24 Jun 2010 07:58:02 -0700
> > Christian De Sainte Marie <csma@fr.ibm.com> wrote:
> > 
> > > sandro@w3.org wrote on 24/06/2010 06:43:24:
> > > > > 
> > > > > RIF specification itself employes a presentation syntax, which is 
> > > > normative and
> > > > > is used in definitions and examples. However, it is ''not'' 
> > > recommended for
> > > > > exchange among different rule systems.
> > > > 
> > > > But that's not true, is it?   BLD and PRD use different presentation
> > > > syntaxes, don't they?  (At least, PRD uses "if" and "then" while BLD
> > > > uses ":-".)
> > > 
> > > And the PS is not normative: only the XML syntax is. All three specs 
> > > (Core, BLD and PRD) are explicit about that.
> > > 
> > > Christian
> > > 
> > > IBM
> > > 9 rue de Verdun
> > > 94253 - Gentilly cedex - FRANCE
> > > Tel. +33 1 49 08 35 00
> > > Fax +33 1 49 08 35 10
> > > 
> > > Sauf indication contraire ci-dessus:/ Unless stated otherwise above:
> > > Compagnie IBM France
> > > Siege Social : 17 avenue de l'Europe, 92275 Bois-Colombes Cedex
> > > RCS Nanterre 552 118 465
> > > Forme Sociale : S.A.S.
> > > Capital Social : 611.451.766,20 ?
> > > SIREN/SIRET : 552 118 465 03644
> > > 
> > 
> 
> 
> Sauf indication contraire ci-dessus:/ Unless stated otherwise above:
> Compagnie IBM France
> Siege Social : 17 avenue de l'Europe, 92275 Bois-Colombes Cedex
> RCS Nanterre 552 118 465
> Forme Sociale : S.A.S.
> Capital Social : 611.451.766,20 ?
> SIREN/SIRET : 552 118 465 03644
> 
Received on Thursday, 24 June 2010 17:02:46 GMT

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