Re[2]: SUO: Re: RE: Logic and Ontology
Dear Collegues,
As I wrote before the problem of "extentional" - "intentional"
descriptions was explored in details in the "Duality principle in a
classification theory".
Such "good sets" ,their members and standard set thery relations are
described by the "Taxonomy", but the dual part "Meronomy" doesn't fix
the sets of objects in principle . Only the subject areas and
properties. A "good" classification system must have the both parts
but in practice very often only the taxonomy is used EXPLICITLY .
And the Meronomy is "hided" in the human minds.
The both parts are used in biology as "Detarminator of the birds
nests" for example.
Regards,
Leonid
mailto:leo@mmk.ru and copy to leo@mgn.ru
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Leonid Ototsky,
www.mgn.ru/~ototsky/ototskyhome.html
Chief Specialist of the Computer Center,
Magnitogorsk Iron&Steel Works (MMK)- www.mmk.ru
Russia
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Friday, March 08, 2002, 11:03:05 PM, you wrote:
SR> I still don't get it ... sorry for being so obtuse :(
SR> From: "John F. Sowa" <sowa@bestweb.net>
>> In that case, there is one fixed universe of discourse, and
>> a predicate such as P(x) is true of some object x if and only if
>> x happens to be a member of the set of things for which P is true.
SR> Well for any given time in any given context (real, imaginary, or
SR> hypothetical) in which we deem that the predicate holds, then (P x) will be
SR> just as good as (member x P). Will it not?
>> However, if you are talking about hypothetical things, plans for
>> the future, or comparisons of the state of the world at different
>> points in time, then the distinction is very important.
>>
>> For example, let the predicate P(x) mean "x is a Boeing 777 airplane".
>>
>> Today, the set of all x's for which P(x) is true is an existing
>> set of things in the world. But for many years, engineers at Boeing
>> were talking about (and defining) the predicate P when no such
>> things existed. They were happily defining the predicate P (in terms
>> of computerized diagrams, simulations, etc.) even though the actual
>> set was empty.
SR> You seem to have switched the context of the model but kept the same context
SR> for the world. In Boeing's design world the set was *not* empty.
SR> Seth Russell