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

Re: [Core][PRD] Definition of safeness

From: Christian De Sainte Marie <csma@fr.ibm.com>
Date: Wed, 17 Jun 2009 10:40:00 +0200
To: Axel Polleres <axel.polleres@deri.org>, Jos de Bruijn <debruijn@inf.unibz.it>, RIF <public-rif-wg@w3.org>
Message-ID: <OF13DE7EC3.36C0D846-ONC12575D8.002F3AF7-C12575D8.002F9BE5@fr.ibm.com>
csma wrote on 17/06/2009 10:15:28:
> 
> Axel Polleres <axel.polleres@deri.org> wrote on 16/06/2009 15:39:41:
> > 
> > blowup for naive normal form DNF transformation is potentially 
> > exponential in the formula size... which makes me a bit nerveous, if 
the 
> > definition contains such a potentially expensive operation. Thus...
> 
> Hmmm... But why would the rule be actually put in DNF? 
> 
> We consider only DNF condition formula, because it makes the 
> definition concise and easy to understand, and because we know that 
> any condition formula can be put in DNF, in principle. 
> 
> But this is about defining the concept; it is not about specifying 
> how to implement it efficiently. 

For the avoidance of doubt, I changed the language introducing the 
transforms, in [1], to:
<<To keep the definitions concise and intuitive, boundedness and safeness 
are defined, below, for condition formulas in disjunctive normal form, 
that can be existentially quantified themselves, but that contain, 
otherwise, no existential sub-formula. The definitions apply to any valid 
RIF-Core condition formula, because they can always, in principle, be put 
in that form, by applying the following syntactic transforms, ...>>

Is that better?

Cheers,

Christian

[1]
http://www.w3.org/2005/rules/wiki/PRD_Safeness_Bottomup#Safeness_in_Core

ILOG, an IBM Company
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
Siège Social : Tour Descartes, 2, avenue Gambetta, La Défense 5, 92400 
Courbevoie
RCS Nanterre 552 118 465
Forme Sociale : S.A.S.
Capital Social : 609.751.783,30 ?
SIREN/SIRET : 552 118 465 02430
Received on Wednesday, 17 June 2009 08:40:40 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Wednesday, 17 June 2009 08:40:41 GMT