Re: A Single Foundational Logic for the Semantic Web

From: Sandro Hawke <sandro@w3.org>
Subject: Re: A Single Foundational Logic for the Semantic Web 
Date: Mon, 29 Apr 2002 14:39:11 -0400

> > [Pat Hayes]

[...]

> > None of this [stuff about programming] has anything to do with what
> > the RDF/DAML/OWL development effort is about, seems to me.
> 
> That statement is both outrageous and totally understandable.  We're
> arguing with some pretty ambiguous terms here.   I'll try to be more
> precise; stop me when go wrong.  (like I have to say that....)

[...]

To me, Pat has hit the nail squarely on the head here (and, conversely,
Sandro is making no sense to me).


If what you want is a univeral computational mechanism, and, moreover, one
that no-one will read directly, then any Turing-complete computational
mechanism will work, be it Post production systems, the lambda calculus,
the Java virtual machine (or whatever it is called), or even deduction in
first-order logic.  Taken in another way, if this *is* what you want, then
there is absolutely no reason whatsoever to use deduction in some logic
that can encode the operations of Turing machines.  You may as well use a
nice (for both humans and non-humans, if this is possible) programming
language.  Computer scientists, and, especially, designers of programming
languages, spend a lot of time on this issue.

If, however, you want to represent information, and, perhaps, even transmit
that information to other computational devices (including both human and
non-human computational devices), then you are in a very different world.
In this better world, computational adequacy is no longer the metric to
use.  Instead some version of representational adequacy is much preferable,
tangled up with computational issues.  Logicians, and, hopefully, designers
of knowledge representation formalisms, spend a lot of time on these issues.

Peter F. Patel-Schneider
Bell Labs Research

Received on Tuesday, 30 April 2002 14:01:16 UTC