From: imaginatorium on
MoeBlee wrote:
> You wrote too many confused and uninformed things for me to even care
> to sort through.

You don't say who "you" is... let me spend a little while guessing. Oh,
but I'll read on while I'm guessing.

> I'll take you up on your last line, though:
>
> > You
> > say you set theory texts define "cardinality" in a certain way which
> > is pretty much circular if relying on cardinality for equinumerosity.
>
> I don't say that. And the definition of 'cardinality of' does use
> 'equinumerosity', but the definition of 'equinumerosity' does not use
> 'cardinality of', so there is not the circluarity you just arbitarily
> claim there to be. I've already been over the subject of mathematical
> definitions with you in other threads. But please do consider all your
> points, objections, and conceptions to be vindicated by my increasing
> apathy to try to bring you to reason about anything at all.

Good news, Lester! I think you're going to win!!

Brian Chandler
http://imaginatorium.org

From: Han de Bruijn on
MoeBlee wrote:

> Han de Bruijn wrote:
>
>>MoeBlee wrote:
>>
>>>Han de Bruijn wrote:
>>>
>>>>But why are the finite ordinals not equivalent with the naturals (I mean
>>>>in mainstream mathematics)?
>>>
>>>The set of finite ordinals IS the set of natural numbers.
>>>
>>>x is a natural number <-> x is a finite ordinal.
>>>
>>>Why don't you just read a textbook?
>>
>>It's all very confusing. Because there also "exist" infinite ordinals,
>>they say.
>
> You won't read a textbook in set theory because it's confusing? So,
> you'd rather remain confused and completely ignorant about set theory,
> while spouting nonsense about it every day on the Internet?

Uh, I'm spouting *sense*.

> Anyway, what is confusing about the theorem that there exist finite
> ordinals and that there exist infinite ordinals?

The latter.

Han de Bruijn

From: Han de Bruijn on
MoeBlee wrote:

> Han de Bruijn wrote:
>
>>MoeBlee wrote:
>>
>>>All cardinals are ordinals (while not all ordinals are cardinals). The
>>>set of natural numbers is the set of finite ordinals which is the set
>>>of finite cardinals. This is standard set theory.
>>
>>Ah! Therefore we can limit ourselves to the naturals and forget all the
>>fuzz about ordinals and cardinals. Because the infinite counterparts of
>>these beasties do not exist in _my_ universe anyway.
>
> Do what you want in _your_ universe. Meanwhile, if you ever get around
> to formulating a mathematical theory, do let us know.

I've formulated more than one, _without_ set theory.

Han de Bruijn

From: Han de Bruijn on
MoeBlee wrote:

> Han de Bruijn wrote:
>
>>The confusion stems from the fact that I cannot and shall not understand
>>the _infinite_ counterparts of the finite cardinals and ordinals.
>
> How can you understand if you won't read a book that explains it? (By
> the way, Halmos is a good book, but it's just an overview; it doesn't
> give you the full explanations that you need.)
>
> So you seem to think it is better to spout nonsense on the Internet
> about a subject you cannot possibly understand since you insist that
> you won't.

How can you say this? I understand very well that infinite cardinals and
ordinals simply do not exist.

Han de Bruijn

From: Virgil on
In article <a4bdc$453876fe$82a1e228$25512(a)news1.tudelft.nl>,
Han de Bruijn <Han.deBruijn(a)DTO.TUDelft.NL> wrote:

> MoeBlee wrote:
>

> > You won't read a textbook in set theory because it's confusing? So,
> > you'd rather remain confused and completely ignorant about set theory,
> > while spouting nonsense about it every day on the Internet?
>
> Uh, I'm spouting *sense*.

Whatever it may be when HdB spouts it, it is nonsense by the time it
appears here.
>
> > Anyway, what is confusing about the theorem that there exist finite
> > ordinals and that there exist infinite ordinals?
>
> The latter.

HdB is too easily confused.