John you stated below:
1. Adding detail (axioms, constraints) makes a theory more
specialized, and it can sometimes create an
inconsistency.
2. Deleting detail makes a theory more generalized, and it
can never make a consistent theory
inconsistent.
In the first case, adding
a conjunctive clause to inhibit the subclass that clause designates would add
detail, and would in complex databases further reduce the number of individuals
predicated by the class _expression_. That can be useful, but the only
inconsistency that can crop in, AFAIK, is a dropped reference - a dangling
reference some call it. Is there another source of inconsistency you have
in mind?
Deleting a conjunctive
clause in a theory's designation _expression_ might increase the number of
individuals covered by the updated _expression_. New facts and rules, added
to a class of facts and rules, should be able to cause inconsistencies by
asserting previously negated facts and rules as should be possible in most practical
applications.
JMHO,
-Rich
Sincerely,
Rich Cooper
EnglishLogicKernel.com
Rich AT EnglishLogicKernel DOT com
9 4 9 \ 5 2 5 - 5 7 1 2
-----Original Message-----
From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx
[mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] On Behalf Of John F. Sowa
Sent: Thursday, January 27, 2011 1:37 PM
To: ontolog-forum@xxxxxxxxxxxxxxxx
Subject: Re: [ontolog-forum] Categorical Views of a Universe
On 1/27/2011 2:56 PM, Ron Wheeler wrote:
> We have tools (Maven) that let describe the dependencies and the
> compatibility between libraries and control how a program (or
library)
> is built, assembled and deployed.
> We have repositories(Nexus and others) that hold many versions of
the
> same library.
> We have forks of libraries that are mostly the same but get
different
> identifiers.
> We use "GroupId", "ArtifactID" and
"Version number" (GAV) to uniquely
> identify a library.
Any or all of those features are completely compatible with the idea of
organizing ontologies in a hierarchy.
> Assumptions about upwards compatibility are commonly made but are
not
> guaranteed and the person defining the dependency has to carefully
> consider the version or version range that the will use.
This is an area where the theory of lattices and software based
on it (of which a great deal exists) can provide more info about
the interrelationships and help test and verify the claims.
Some principles are simple and guaranteed:
1. Adding detail (axioms, constraints) makes a theory more
specialized, and it can sometimes create an
inconsistency.
2. Deleting detail makes a theory more generalized, and it
can never make a consistent theory
inconsistent.
Others may require more testing (which could, in the worst case
be undecidable). But trying to do the test can never hurt
--
the worst it might do is to run an unused computer for a whole
weekend without reaching a conclusion. That doesn't prove that
the system is consistent or inconsistent, but it could be a
warning.
John
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