Hi Richard --
You wrote
I still have the impression
that formal model
theory is an academic exercise which has little to
do with
meaning in the real world. I don't envision
doing anything
with model theory when I am using mKE to process
knowledge
representations.
Well yes, that's what most software engineers would say.
The problems with such an empirical approach usually don't show up for a long time, but when they do, they are disastrous.
As an analogy, consider the ancient decision to not do array bounds and pointer checking in C and other languages, for efficiency reasons. Now we have huge numbers of buffer overflow attacks.
Or, consider that SQL never had a model theory. Now we have two major commercial implementations of SQL that produce different results from the same query over the same data.
The center of gravity of these concerns is how things go wrong on the Web [1], but I understand that's precisely where you are working.
We take our own advice on this -- our system is based on a model theory [2].
Hope this helps.
Best regards, -- Adrian
[1] http://www.w3.org/2004/12/rules-ws/paper/19
[2] Backchain Iteration: Towards a Practical Inference Method that is Simple
Enough to be Proved Terminating, Sound and Complete. Journal of Automated Reasoning, 11:1-22
Internet Business Logic
A Wiki and SOA Endpoint for Executable Open Vocabulary English over SQL and RDF
Online at www.reengineeringllc.com Shared use is free
Adrian Walker
Reengineering
2009/3/18 Richard H. McCullough <rhm@xxxxxxxxxxxxx>
Adrian
I have not yet been convinced that any such "extra"
interpretation
is necessary. I still have the impression
that formal model
theory is an academic exercise which has little to
do with
meaning in the real world. I don't envision
doing anything
with model theory when I am using mKE to process
knowledge
representations.
Showing that mKR can be translated to IKL does
not imply
that I'm going to translate to IKL as part of every
application
of mKR. In fact, some people might choose to
translate
from IKL to mKR to take advantage of mKE
tools.
Dick McCullough Ayn Rand do speak od mKR done; mKE do enhance od Real
Intelligence done; knowledge := man do identify od existent
done; knowledge haspart proposition list; http://mKRmKE.org/
----- Original Message -----
Sent: Wednesday, March 18, 2009 5:19
PM
Subject: Re: [ontolog-forum] Requirements
of computer language semantics
Hi John -- You wrote Other
things being equal, it makes more sense to try
to map a new
language L1 to some previously defined
and analyzed language
than to try to define the
semantics for L1 from
scratch.Actually, you can just construct a model theory for L1
directly. This may of course lead you to modify L1. But when the
model theory is done, you can use it as a gold standard for implementing a
reasoner. That's way easier and less error prone than trying to do the
same kind of thing via L1---> L2. It saves you having to prove the
correctness of the --->. It also gets rid of a layer of
interpretation or compilation at run
time.
Cheers, -- Adrian Internet Business Logic A Wiki and SOA
Endpoint for Executable Open Vocabulary English over SQL and RDF Online at
www.reengineeringllc.com
Shared use is free Adrian Walker Reengineering
On Wed, Mar 18, 2009 at 8:02 PM, John F. Sowa <sowa@xxxxxxxxxxx>
wrote:
Chris,
I
agree with the technical points you made, but the judgment
about what
makes "more sense" is debatable:
CM> Other things being equal, it
makes a great deal more sense
> to provide a semantics for L1
directly [than to define the
> semantics by translation to a
previously defined language L2].
Interoperability is always a major
practical concern in comp. sci.,
and a translation from a new language L1
to a previously defined
and analyzed language L2 can help answer many
important questions:
1. Are they logically equivalent or can
one be mapped to a subset
of the other?
2. If
the answer to #1 is no, then is there some subset L1' of L1
and L2' of L2 such that L1' and L2' are logically equivalent?
Are those subsets L1' and L2' big enough to be
useful?
3. Which reasoning engines already available for L2 can
be
be used for L1 or some subset of L1?
If the model
theory of L2 is defined independently of L1, it is
much harder to answer
these questions.
For a previously unanalyzed language such as mKR,
many of us
have little or no confidence in its consistency. It's
quite
possible that if Dick (or one of his colleagues) tried to
map
mKR expressions to a previously defined language, they
might encounter
some serious difficulties. Therefore, they
might choose to redefine
the troublesome features of mKR
in a way that simplifies the
translation.
So I would argue for the following
procedure:
Other things being equal, it makes more sense
to try
to map a new language L1 to some previously
defined
and analyzed language than to try to define
the
semantics for L1 from scratch.
John
_________________________________________________________________
Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/
Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/
Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
Shared Files: http://ontolog.cim3.net/file/
Community Wiki: http://ontolog.cim3.net/wiki/
To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J
To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx
_________________________________________________________________
Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/
Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/
Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
Shared Files: http://ontolog.cim3.net/file/
Community Wiki: http://ontolog.cim3.net/wiki/
To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J
To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx (01)
|