Re: Is {{}} a valid construct?

From: mAsterdam <mAsterdam_at_vrijdag.org>
Date: Tue, 06 Feb 2007 02:52:15 +0100
Message-ID: <45c7df32$0$323$e4fe514c@news.xs4all.nl>

(stopped x-post)
Neo wrote:

 > Walt wrote:
>> It's important to realize that every symbol inside a computer is a metaphor.
>> A transparent zone is a metaphor for a zero,  and an opaque zone is a
>> metaphor for a one  (on an optical disk).  As we proceed up the levels of
>> abstraction from there,  it's all metaphor.

>
> True we can use almost anything as a metaphor, but how can we use
> nothing as a metaphor for something?
>

>> Not that this has any bearing on the question Neo keeps asking.

>
> It does. So I now ask you, suppose my universal set contains just one
> "element" as follows:
>
> U = { {} }

Accepting this notation as far as I get it, U cannot be the Universal set (barring an escape signification/meaning); it is a set with one element only: the empty set, signified by '{}'.

> What then is NOT {} ?

What do you mean to say with 'NOT {}'?
All the sets but U? Or is it 'there is no {}'(there is no empty set)? Received on Mon Feb 05 2007 - 19:52:15 CST