- From: Hassan Aït-Kaci <hak@ilog.com>
- Date: Tue, 16 Jan 2007 16:45:59 +0100
- To: Gerd Wagner <wagnerg@tu-cottbus.de>
- CC: W3C RIF WG <public-rif-wg@w3.org>
Gerd Wagner wrote: >>I have finalized the writeup on data models as constraints. >>It is available as >>http://koala.ilog.fr/wiki/pub/Main/HassanAitKaci/semwebclp.pdf >>Comments are welcome. > > > Hassan, it seems that you have completely ignored the > fundamental issue of negation-as-failure (NaF), also > called "negation-by-default", and the related issue > of open vs. closed predicates in your paper. > > Why? Because you didn't consider that (yet) in your > OSF formalism? Hi Gerd, Thanks for your comment on my paper: you must be the fastest reader that I have come across in my life! ;-) Re. your comment, I must say thay I do not quite understand what it has to do with either the topic of the article, nor what it means. What I wrote about is simple: because CLP makes rules and constraints orthogonal, it offers a way to use rules over arbitrary data models - not just data and FOTs. I then focused on the OSF and DL formalisms seen as constraint systems for objects and inheritance. The nature of the rules is *not* important and may be of all kinds including Horn, (with or without negations or all kinds), Production, YouNameIt, ... > How can you capture SQL, Prolog and production rules > without supporting NaF? Again the focus of my paper is *NOT* on the rules but (as the title states it clearly) about *data models as constraint systems*. Also, the nature of the paper is that of a (semi-formal) tutorial - not an exhaustive survey about all known or possible ways to conjugate rules and data. Perhaps you should write such an article? :-) This notwithstanding, the way negation is handled for OSF terms (see Section 3.1.5) implicitly uses a CWA on the set of sort. I admit that I should make this fact clear. Finally, this is just a journal article, not a book! Isn't a 40-page paper, in 10pt font fullpage layout, long enough for you? :-) At any rate, I am sorry that you find my work of debatable interest for your needs, and I apologize for disappointing your expectations. Be that a it may, thanks again for caring to give me some feedback with your comments. > -Gerd Regards, -hak -- Hassan Aït-Kaci ILOG, Inc. - Product Division R&D tel/fax: +1 (604) 930-5603 - email: hak @ ilog . com
Received on Tuesday, 16 January 2007 15:46:58 UTC