- From: Peter F. Patel-Schneider <pfps@inf.unibz.it>
- Date: Tue, 09 May 2006 05:02:03 -0400 (EDT)
- To: bry@ifi.lmu.de
- Cc: public-rif-wg@w3.org
From: Francois Bry <bry@ifi.lmu.de> Subject: Re: "Semantics" vs. "No Semantics" Date: Tue, 09 May 2006 10:18:54 +0200 > > Gary Hallmark wrote: > > > > I agree that there are many ways to approach semantics. While I'm not > > sure I would characterize model-theoretic semantics as more or less > > abstract than other approaches, I do fear that a model-theoretic > > semantics will be of little help > > to the implementors of RIF translators and associated rule engines. > > Looking at other W3C formal semantic specifications for guidance, I > > find http://www.w3.org/TR/xquery-semantics/ to be a good approach. > > Formal XQuery semantics are specified using RULES. Why can't we > > specify RIF semantics using rules? We could even write those rules > > using RIF. > > > > Look, I do not want to start a religious war about "abstract semantics". > All what I mean is the following: > > If S1 is a semantics specifying more aspects of a language than a > semantics S2 for this language, then S1 is more abstract than S2. How is S1 more "abstract"? Isn't it just "incomplete", or "vague", or "unfinished"? > This is the standard meaning of "abstract" in Computer Science. Not in my view, at least not without a whole lot of other caveats. > Whether a model theopry helps or not implementi ng rule engines, is an > important issue. Many (among others myself) think that a model theory > helps avoiding implementations that diverge as of what they compute. > > Implementations diverging on "how they compute" is good. Implementations > diverging on "what they compute" is bad. This is a common view in > stardizing. Sure. > All we need is a good way to properly specify the "what" and leave out > enough of the "how" for people to realize not only one implementations > but severla ones imporving over the foremr ones. Find suchy a good way, > and, I am confident, it won't be difficult to re-express ist as model > theory. Well, I don't see how this is going to get to you to anything that is more "abstract" than model theory. > Another point: A Tarskian model theory is also specified using rules... I don't think that looking at Tarskian model theory as a set of rules is an interesting approach. > François peter
Received on Tuesday, 9 May 2006 09:02:27 UTC