From: Virgil on
In article
<41a66545-c0bb-44e3-bb41-1fdaf0c83d71(a)j4g2000yqh.googlegroups.com>,
WM <mueckenh(a)rz.fh-augsburg.de> wrote:

> On 24 Jun., 01:02, "Mike Terry"
> <news.dead.person.sto...(a)darjeeling.plus.com> wrote:
>
> > > a) Does this list contain the anti-diagonal of
> > > (..., An, ... A2, A1, A0, L0)?
> >
> > This is not a list of numbers. �L0 is not a number, it is a list.
> >
> > Therefore (..., An, ... A2, A1, A0, L0) does not have an anti-diagonal.
>
> You are wrong.
>
> The symbols above abbreviate the sequence of lists
>
> An
> ...
> A0
> L0
>
> Each of them has an antidiagonal that either is not in the list (then
> the set of all of them is unlistable) or is in a list. Then Cantors
> argument is wrong.

If one has only a list of lists, then its union can be listed and
therefore has many "antidiagonals".
From: Virgil on
In article
<04127510-c0d4-4b53-b536-f87e1ac60a2c(a)j8g2000yqd.googlegroups.com>,
WM <mueckenh(a)rz.fh-augsburg.de> wrote:

> On 24 Jun., 02:39, Sylvia Else <syl...(a)not.here.invalid> wrote:
> > On 23/06/2010 8:44 PM, WM wrote:
> >
> >
> >
> >
> >
> > > On 23 Jun., 06:47, Sylvia Else<syl...(a)not.here.invalid> �wrote:
> >
> > >> Rather than argue that VMs proposition fails on that point, I wanted to
> > >> address the flaw, in order to find a more substantial objection.
> >
> > > My initials ar WM.
> >
> > > There is no flaw in the argument: Your bijection either contains all
> > > constructed antidiagonals. Then a list contains also its antidiagonal,
> > > because every list has an antidiagonal and your bijection (that is
> > > only a permutation of my list) contains all lines and antidiagonals.
> > > I.e., there is no missing antidiagonal of a "limit" list outside of
> > > the bijection.
> >
> > > Or there is a last diagonal of the limit list that does not belong to
> > > your bijection (and to my list). Then there is a countable set (the
> > > set that includes this last diagonal) that is not listable.
> >
> > > Think over that only a little bit. It is not difficult to understand.
> >
> > > Regrads, WM
> >
> > Thing is, I just cannot see that you've constructed a countable set that
> > should contain its own anti-diagonal when expressed as a list.
>
> When it does not contain it, then the antidiagonal is not listed. That
> is all.


>
> > All
> > you've done is construct a countable set of countable sets, each of
> > which contains the anti-diagonals of its predecessors, but none of which
> > by construction can be expected to contain its own anti-diagonal.
>
> That is why I did it. The set of elements of L0 and antidiagonals A0,
> A1, ... is countable, but cannot be listed.

Nonsense. {L0_0, A0, L0_1, A1, L0_2, A2, ...} is just such a list as WM
clams cannot exist.
> >
> > You've then claimed, but without any kind of formal argument, that if
> > you take this to the limit,
>
> Why should there be a limit? Why should I agrre to take this to a
> limit? There is no limit in n. Every one is followed by another one.

The elements of N have no limit, but N still exists.

Any process that can be endlessly iterated need not have any "limit" but
the set of all its iterations still can exist, just as N does.
>
> > the result is a countable set that should
> > contain its own anti-diagonal when expressed as a list.
>
> Then Cantor's argument would fail.

Which is why it never happens, at least with things like countable sets
of reals or endless binary sequences. For each such there is an
"antidiagonal" which is not a member of it (in fact lots and lots of
antidagonals).



> There are no other escapes: Either
> there is some list that contains its antidiagonal or there is no list
> that contains it.

If the listed things are functions from N to a set of at least two
elements, every one has at least one "antidiagonal". In fact lots and
lots of them. At least as many antidiagonals as members.
From: WM on
On 24 Jun., 09:34, Virgil <Vir...(a)home.esc> wrote:

> > The symbols above abbreviate the sequence of lists
>
> > An
> > ...
> > A0
> > L0
>
> > Each of them has an antidiagonal that either is not in the list (then
> > the set of all of them is unlistable) or is in a list. Then Cantors
> > argument is wrong.
>
> If one has only a list of lists,

There is always, at every stage of the construction, one single list
like Ln above, that either contains or not its antidiagonal.

Thise prodedure is abbreviated by
(..., An, ... A2, A1, A0, L0)
but of course there cannot appear at any stage a list without first
line.

> then its union can be listed and
> therefore has many "antidiagonals

Before doing so, you first need the elements.
There are two alternatives:
1) There is a list in the construction that contains its antidiagonal.
Then Cantor's proof is wrong.
2) There is no list in the construction that contaiuns its
antidiagonal, then the antidiagonal cannot be placed at position 0 at
the previous list without generating another list and another
antidiagonal. Therefore, the set of the lines of L0 and the set of all
antidiagonals occuring during construction cannot be listed.

It is as simple as that.

It is not a big deal. Set theory shows many contradictions arising
from the idea, that from "every n in N can be constructed" it is
implied that "N can be constructed". This is wrong, because for every
n, there is an infinite set of unconstructed elements of N.

This is so for *every* n in N. Hence, N cannot be constructed, and no
proof for all n in N has ever been valid.

.... classical logic was abstracted from the mathematics of finite
sets and their subsets .... Forgetful of this limited origin, one
afterwards mistook that logic for something above and prior to all
mathematics, and finally applied it, without justification, to the
mathematics of infinite sets. ... As Brouwer pointed out this is a
fallacy, the Fall and Original sin of set theory even if no paradoxes
result from it. [Weyl, Hermann (1946), "Mathematics and logic: A
brief survey serving as a preface to a review of The Philosophy of
Bertrand Russell", American Mathematical Monthly 53: 2–13.]

Regards, WM
From: Virgil on
In article
<ff595e3b-8160-4655-a12a-641a304b86ff(a)y4g2000yqy.googlegroups.com>,
WM <mueckenh(a)rz.fh-augsburg.de> wrote:

> On 24 Jun., 09:34, Virgil <Vir...(a)home.esc> wrote:
>
> > > The symbols above abbreviate the sequence of lists
> >
> > > An
> > > ...
> > > A0
> > > L0
> >
> > > Each of them has an antidiagonal that either is not in the list (then
> > > the set of all of them is unlistable) or is in a list. Then Cantors
> > > argument is wrong.
> >
> > If one has only a list of lists,
>
> There is always, at every stage of the construction, one single list
> like Ln above, that either contains or not its antidiagonal.

Show me a list of endless binary sequences or real numbers that you
think contains what may reasonably be called an antidiagonal for it. I
do not believe that any such list can exist.

Cantor's argument satisfies me that for lists of binary infinite
sequences, no antidiagonal can ever be a member of it.
>
> Thise prodedure is abbreviated by
> (..., An, ... A2, A1, A0, L0)
> but of course there cannot appear at any stage a list without first
> line.

But that list can be rearranged into a more standard form, for example
with the An and the members of L0 listed alternatingly, and from such a
rearrangement a non-member anti-diagonal can be constructed.
>
> > then its union can be listed and
> > therefore has many "antidiagonals
>
> Before doing so, you first need the elements.
> There are two alternatives:
> 1) There is a list in the construction that contains its antidiagonal.

Which Cantor's argument shows cannot happen.

> Then Cantor's proof is wrong.


> 2) There is no list in the construction that contaiuns its
> antidiagonal, then the antidiagonal cannot be placed at position 0 at
> the previous list without generating another list and another
> antidiagonal. Therefore, the set of the lines of L0 and the set of all
> antidiagonals occuring during construction cannot be listed.

They can easily be listed, as I have several times shown.
Wm has to get over the notion that the elements to be listed cannot be
rearranged.
>
> It is as simple as that.
>
> It is not a big deal. Set theory shows many contradictions arising
> from the idea, that from "every n in N can be constructed" it is
> implied that "N can be constructed".

In, for example, FOL+ZFC, there is no assumption that every n in N "can
be constructed". What is assumed is that there exists a set, along with
all its elements, having the properties that we want for N and its
elements , which we then call N.



This is wrong, because for every
> n, there is an infinite set of unconstructed elements of N.

But we do not "construct" any of them. Though we do construct various
naming conventions for elements of N.
>
> This is so for *every* n in N. Hence, N cannot be constructed

No one claims it can be. But it can be, and usually is, assumed without
being constructed.

There is no reason to despise any axiom system, however much it may seem
to diverge from physical reality, unless it allows proof of a statement
of the form "Both P and not P".

WM, worshipping physics, does not understand that there are areas of
mathematics completely outside of physics, so would hamper mathematics
by forcing it not to look outside of physics.

If WM could have forced this, internet commerce, for example, would be
impossible.
From: WM on
On 24 Jun., 11:04, Virgil <Vir...(a)home.esc> wrote:

> > Thise prodedure is abbreviated by
> > (..., An, ... A2, A1, A0, L0)
> > but of course there cannot appear at any stage a list without first
> > line.
>
> But that list can be rearranged into a more standard form, for example
> with the An and the members of L0 listed alternatingly, and from such a
> rearrangement a non-member anti-diagonal can be constructed.

What should that be good for? The countable set under investigation
contains the antidiagonal of the arragement that I prescribed.

Your arguing reminds of another argument: I can eat cherries,
therefore the list is neither complete nor incomplete.

I for my person would not accept that. Perhaps set theorists have
another taste.
>

> > It is as simple as that.
>
> > It is not a big deal. Set theory shows many contradictions arising
> > from the idea, that from "every n in N can be constructed" it is
> > implied that "N can be constructed".
>
> In, for example, FOL+ZFC, there is no assumption that every n in N "can
> be constructed". What is assumed is that there exists a set, along with
> all its elements, having the properties that we want for N and its
> elements , which we then call N.

And being ready to be used for the construction of a bijection.
>
>  This is wrong, because for every
>
> > n, there is an infinite set of unconstructed elements of N.
>
> But we do not "construct" any of them. Though we do construct various
> naming conventions for elements of N.

Bijections from M to N are constructed. Sequences (having natural
indices) are constructed. Many constructivists do not believe in
uncountability but in N because N can be constructed.

Regards, WM