Re: Well Ordering the Reals



Tony Orlow <aeo6@xxxxxxxxxxx> writes:

> David Kastrup said:
>> Tony Orlow <aeo6@xxxxxxxxxxx> writes:
>>
>> > David Kastrup said:
>> >> Tony Orlow <aeo6@xxxxxxxxxxx> writes:
>> >>
>> >> > So, countable means finite but unbounded, as I've said for months.
>> >>
>> >> No. It does not mean finite either which way. It does not mean
>> >> finite for the member values (in fact, it means nothing whatsoever
>> >> for the member values except that they are distinguishable), and it
>> >> certainly does not mean finite for the set.
>> >
>> > Essentially it does. A countable set consists only of elements
>> > with a finite number of predecessors.
>>
>> An infinite number of them, yes. According to which definition
>> does that make the set finite?
>
> The definition that says the set is infinite iff it contains an
> infinity NUMBER of elements. This is not the Dedekind definition,
> but the new, improved Orlow definition.

So {infinity} is supposed to be an infinite set? Or do you mean any
set X with an infinite cardinality(X) is supposed to be infinite?
What does it mean to have an infinite cardinality, then? Your
definition seems circular.

>> Fine. So you agree that the set of (finite) naturals as defined by
>> the Peano axioms is infinite as defined by Dedekind.
> Sure, as defined by Dedekind, but I think that definition has
> issues, because the set SIZE is not actually infinite, but
> unboundedly finite.

Unboundedly finite is an oxymoron.

>> >> And that means that _any_ unbounded (and any non-empty open)
>> >> ordered set is infinite.
>> >
>> > In the Dedekind sense, yes, I know. I don't need this repeated.
>>
>> But that's what mathematicians are talking about when talking about
>> "infinite sets", and you have not come up with any different
>> definition. So you have no business complaining.

> I most certainly have said that I believe that definitions can start
> with sets or with quantities, and have offered a set with an
> infinite QUANTITY of elements as the difnition of an infinite set.

Then you need to define "infinity QUANTITY". You are being circular
(and self-inconsistent, but that's another matter).

--
David Kastrup, Kriemhildstr. 15, 44793 Bochum
.



Relevant Pages

  • Re: Infinity
    ... > The definition of 'Dedekind infinite' is: ... the proof of the Banach-Tarski theorem does not use ... The theorem stands in the primitive language of set theory ...
    (sci.math)
  • Re: Ultimate debunking of Cantors Theory
    ... infinite' that is just equivalent to an ordinary set theoretic ... definition is Dedekind infinite by Dedekind's. ... not working in an axiomatic set theory, ... I posted a ratio of nodes and edges that I agree converges to 1 or to ...
    (sci.math)
  • Re: Infinity
    ... Tony Orlow wrote: ... The definition of 'Dedekind infinite' is: ... The theorem stands in the primitive language of set theory ...
    (sci.math)
  • Re: Ultimate debunking of Cantors Theory
    ... The only one mislead is WM. ... The Dedekind criterion for infiniteness refers to COMPLETED sets. ... willingness to regard infinite sets as objects to be treated in much ...
    (sci.math)
  • Re: Ultimate debunking of Cantors Theory
    ... misunderstood it and mislead mathematics more than any one before him. ... The only one mislead is WM. ... The Dedekind criterion for infiniteness refers to COMPLETED sets. ... willingness to regard infinite sets as objects to be treated in much ...
    (sci.math)