- From: Axel Polleres <axel.polleres@deri.org>
- Date: Fri, 13 Jul 2007 14:52:14 +0100
- To: Sandro Hawke <sandro@w3.org>, "Public-Rif-Wg (E-mail)" <public-rif-wg@w3.org>
Sandro Hawke wrote: >>>> class NAF >>>> >>>> subclass StratifiedNaf >>>> >>>> subclass WellFoundedNaf >>>> >>>> subclass StableModelNaf >> >>Hmmm, you mean to say that I need to specify which naf I use ALWAYS? >>In this case we rather call the first class >> PerfectModelNaf >>since this is what it is on the pure semantic basis. The perfect model >>semantics is simply only defined for stratified programs. Systems which >>implement it -- and it seems that there are no systems which only allow >>strat naf and do check is -- norlmally deploy perfect model semantics >>and just fault in case the program is unstratified. > > > Ah, that makes sense. One might also call it "StratifiedOnlyNaf", > maybe... > > >>To call it stratnaf sounds like stratnaf would be something *different* >>from well-founded or stable negation, which it is not in case the >>program is stratified. Why I wanted to have the subclassing in first >>place was because my understanding was that I wanted to express that in >>the stratified case both well-founded and stable coincide. > > I don't think the class hierarchy gives you that in any formal way. Can > you say what you were thinking/hoping the class hierarchy would provide > here? naf was negation as failure in general, smnaf and wfnaf were subclasses, I didn't have a specific stratnaf. but since smnaf and wfnaf were subclasses of naf, a stratified program using e.g. wfnaf would have automatically been in the strat dialect (by wfnaf being naf due to subclassing) axel > Did you want RIF documents to sometimes be written not saying > which kind of NAF was intended? > > -- Sandro > > > -- Dr. Axel Polleres email: axel@polleres.net url: http://www.polleres.net/
Received on Friday, 13 July 2007 13:52:22 UTC