Re: "Semantics" vs. "No Semantics"

From: Francois Bry <bry@ifi.lmu.de>
Subject: Re: "Semantics" vs. "No Semantics"
Date: Tue, 09 May 2006 11:14:14 +0200

> 
> Peter F. Patel-Schneider wrote:
> > 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"? 
> 
> What i mentioned is  the definition I know for "abstract".

> >> This is the standard meaning of "abstract" in Computer Science.
> >>     
> >
> > Not in my view, at least not without a whole lot of other caveats.
> >   
> 
> Please, give a definiton of "abstract" covering the usages of this word
> in many fileds such as programming and modseling languages, knowledge
> rep[esentation, and also logic...


Well, one could use some of the definitions from Wikipedia
(http://en.wikipedia.org/wiki/Abstract)

********************
# Abstraction (computer science), a mechanism and practice to reduce and
	factor out details so that one can focus on few concepts at a time 
# Abstraction (mathematics), the process of extracting the underlying
	essence of a mathematical concept, removing any dependence on real
	world objects 
# Abstraction (sociology), the varying levels at which theoretical concepts
	can be understood 
********************

Or from Wiktionary (http://en.wiktionary.org/wiki/abstract)

********************
Noun
abstract
   1. That which comprises or concentrates in itself the essential
   qualities of a larger thing or of several things. Specifically: A
   summary or an epitome, as of a treatise or book, or of a statement; a
   brief. 
          * Watts - An abstract of every treatise he had read. 
          * Ford - Man, the abstract Of all perfection, which the
	  workmanship Of Heaven hath modeled. 
   2. A state of separation from other things; as, to consider a subject in
   the abstract, or apart from other associated things. 
********************

I view the mathematical variant as closest to what the term usually means
in knowledge representation and logic.  Any of these are much better than
"specifying more aspects", which could mean many things that don't appear
to me to be at all like abstraction.


> >> 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.
> 
> Well, it is defined in terms of a function on formulas assigning to each
> (sub)formula a truth value.

Sure, but so what?

> Pointing to the fact that this is very close to a rule notion, is, in
> our context, surely interesting.

In what way is it close to a rule?  I view it as very far away from a
procedural rule, for example.

> François
> 
> PS: It has often turned out quite unfortunate to say, in Sciences, "this
> is not an interesting approach.  ;-)

Agreed.  

peter

Received on Tuesday, 9 May 2006 13:03:25 UTC