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Guest
Posted: Tue Aug 29, 2006 6:14 am
Dik T. Winter schrieb:


Quote:
It is your lack of a proper proof that if each digit of a number can
be indexed that number can be covered. And such a proof does not
exist.

I do not see how I could avoid my conclusion. But if you are so sure
then give us at least one example how you completely index a number
without covering all the preceding numbers.

I have done so many times, and am doing it here again.

You gave an example how a number of the form 0,111...1 with n digits
indexes the n-th digit but does not cover all digits with m =<n ???

No, because that does not exist.

How then can you believe and assert that the number 0.111... which has
*only finitely indexable positions* could be completely indexed but not
covered.

Regards, WM
Guest
Posted: Tue Aug 29, 2006 6:17 am
Dik T. Winter schrieb:

Quote:
In article <1156689126.335154.133150@h48g2000cwc.googlegroups.com> mueckenh@rz.fh-augsburg.de writes:
Dik T. Winter schrieb:
The first part of his first proof shows that a complete ordered field
has cardinality larger than the natural numbers. In his proof he did
not rely an any properties of the reals other than that they form a
complete ordered field (he uses reals to exemplify).
...
Note what I wrote: "in his proof he did not rely on any properties of
the reals other than that they form a complete ordered field". What
other properties of the reals did he use?

He had no field and he used no filed. What is a field without the
axioms of the field? Nothing. Cantor disliked axioms if he did not hate
them. His only concern were numbers, numbers, numbers and their
*reality*. No fields and no axioms.

Perhaps. I thought we were discussing current set theory. And not what
in some time long ago was et theory. He may not have liked them, but in
current terminology "the first proof shows that a complete ordered field
has cardinality larger than the natural numbers".

In the terminology of the next century it may show even other things,
more general perhaps, with even more insight. I was discussing what
Cantor did. You were accusing me that I had not understood or misquoted
him.
Quote:

He wrote that it was a simpler proof for his first theorem, i.e. the
theorem that the reals are uncountable.

And he did *not* write that.

Aus dem in =A7 2 Bewiesenen folgt n=E4mlich ohne weiteres, da=DF

Quoting again only in part. I will quote the translation I gave, with
annotation of the complete paragraph, not only the part you like to quote:
In the article, titled: "Über eine Eigenschaft des Ombegriffs aller
reellen algebraischen Zahlen (Journ. Math. Bd. 77, S. 258) [hier
S. 115], can for the first time be found a proof of the theorem
that there are infinite sets that are not in bijection with the set of
natural numbers 1, 2, 3, ..., v, ..., or, as I say in general, do not
have the same cardinality as the natural numbers 1, 2, 3, ..., v, ... .
So apparently he is thinking that his first article proves the theorem
that there are sets that are not in bijection with the natural numbers.
Which is true.

Of course: The set of the reals and the set of the transcendental
numbers are such sets. So he has the right to speak generally about
"sets". Which mathematician would not like to generalize his theorems?

Quote:
From what has been proven in section 2 follows that e.g. the
set of real numbers in an arbitrary interval can not be put in
a sequence w_1, w_2, w_3, ..., w_v, ... .
So he is now thinking that that proof was just an example for such a set.
Which it is. The "beispielsweise" is telling.
It is however possible to construct a much simpler proof for
that theorem that is independent from the observation of irrational
numbers.

Independent of the *necessary use* of irrational numbers.

Quote:
And the "that theorem" (in German "jenem Satze") can, in my opinion only
refer to the theorem mentioned in the first sentence in this paragraph.

That theorem the proof of which depends on irrational numbers.

Regards, WM
Virgil
Posted: Tue Aug 29, 2006 2:47 pm
Guest
In article <1156842504.966630.131290@h48g2000cwc.googlegroups.com>,
mueckenh@rz.fh-augsburg.de wrote:

Quote:
Dik T. Winter schrieb:


Let us remove omega from that set. What is the resulting cardinality?

Not an actually infinite one, because without omega there are only
finite natural numbers.

It is not how big the numbers are but how many of then that is at issue,
and there are still more than any finite number of them, which in any
reasonable sense means infinitely many of them.
Quote:

As there is a bijection between that set and the set including omega, their
cardinalities are the same.

No. Without omega there is no actual infinity.

While there is no "acual infinity" as a *member* of the set, that is not
what is being discussed.
Quote:

Your example shows very clear that either both LUBs have to be included
- or none. In my opinion we choose none. But whatever you choose, you
cannot avoid to see the symmetry, can you?

I see the symmetry, I also choose none. And I think I have stated that
already.

Fine. That means there is no actual infinity.

No, that means that there is no actual "Mueckenh".

Quote:
But if there are infinitely many naturals then the infinite sum is
necessary.

Not at all. Why do we need it?

You should know that the n-th natural number is defined by the sum of
the number n-1 plus 1 (Peano). This can be retraced to the sum of n
1's. What is there to be defined? If there are infinitely many naturals
(and if infinity is a number),

"Infinity" is not a thing, as there are too many different sorts of
infinteness to be any one thing. There are types of "numbers" which do
not have the property of being finite.




Quote:
then there is at least one infinite sum
of 1's (one from each natural).

Why? Such extraordinary claims require extraordinary proofs, and
"Mueckenh" cannot give any proof at all.


Quote:

OK, I kind of understand. I do not state that infinity is a number
aleph_0.
There exists a host of infinities. And aleph_0 is the infinity that gives
the equivalence class of sets that are in bijection with the set of
natural numbers; the canonical set with cardinality infinity.

If aleph_0 > n for n e N, and if there are even numbers x > aleph_0,


Who says that there are even numbers greater than alef_0? Name one.



Quote:
But indeed. If the ordinality of a set is infinite (w or larger), then
so is its cardinality (aleph-0 or larger). On the other hand, if the
cardinality of a set is infinite (aleph-0 or larger), and if it can be
well-ordered, so is its ordinality after well-ordering (w or larger).

As long as the set of natural numbers includes only finite numbers, its
cardinal number is also finite.

Except when it is not. And the cardinality of the set of naturals is
larger ( in the Cantor sense of cardinality) than any natural.
I.e., there is no natural large enough to be the cardinality of the set
of all naturals.
Quote:

Regards, WM
Virgil
Posted: Tue Aug 29, 2006 2:56 pm
Guest
In article <1156842646.101182.155640@74g2000cwt.googlegroups.com>,
mueckenh@rz.fh-augsburg.de wrote:


Quote:
You seem to misunderstand the tree. If the diagonal is in Cantor's
list, then 1/3 is in my tree. Can you give a reason why it should not
(other than that then set theory is inconsistent)?

Or, what is much more likely than the inconsistency of something so
thoroughly vetted as standard set theories, is the likelihood that
"Mueckenh"'s theory is inconsistent.

Quote:
Either you agree that all the edges of my tree are countable or you
agree that Cantor's diagonal is uncountable.

The set of edge is countable, but, for an infinite binary tree, the set
of paths is not.
Virgil
Posted: Tue Aug 29, 2006 2:59 pm
Guest
In article <1156842898.805375.169610@h48g2000cwc.googlegroups.com>,
mueckenh@rz.fh-augsburg.de wrote:

Quote:
How then can you believe and assert that the number 0.111... which has
*only finitely indexable positions* could be completely indexed but not
covered.

Indexing does not require "covering" in any sense except that each
object to be indexed is "covered" by having an index assigned to it.
Virgil
Posted: Tue Aug 29, 2006 3:06 pm
Guest
In article <1156843043.617422.7230@i3g2000cwc.googlegroups.com>,
mueckenh@rz.fh-augsburg.de wrote:

Quote:
Dik T. Winter schrieb:

In article <1156689126.335154.133150@h48g2000cwc.googlegroups.com
mueckenh@rz.fh-augsburg.de writes:
Dik T. Winter schrieb:
The first part of his first proof shows that a complete ordered
field
has cardinality larger than the natural numbers. In his proof he
did
not rely an any properties of the reals other than that they form
a
complete ordered field (he uses reals to exemplify).
...
Note what I wrote: "in his proof he did not rely on any properties of
the reals other than that they form a complete ordered field". What
other properties of the reals did he use?

He had no field and he used no filed. What is a field without the
axioms of the field? Nothing. Cantor disliked axioms if he did not hate
them. His only concern were numbers, numbers, numbers and their
*reality*. No fields and no axioms.

Perhaps. I thought we were discussing current set theory. And not what
in some time long ago was et theory. He may not have liked them, but in
current terminology "the first proof shows that a complete ordered field
has cardinality larger than the natural numbers".

In the terminology of the next century it may show even other things,
more general perhaps, with even more insight. I was discussing what
Cantor did. You were accusing me that I had not understood or misquoted
him.

Cantor required of the his set of reals, with its usual arithmetic and
order properties, all those properties that we now collect under the
rubric of a complete Archimedean ordered field, even though he did not
call it that.

Or does "Mueckenh" claim that there is some property of a complete
Archimedean ordered field that Cantor did NOT assume his notion of the
reals had?
Dik T. Winter
Posted: Tue Aug 29, 2006 7:29 pm
Guest
In article <1156689269.210304.49390@m73g2000cwd.googlegroups.com> mueckenh@rz.fh-augsburg.de writes:
Quote:
Dik T. Winter schrieb:
....
So you can compute all solutions of a polynomial equation even of
higher than fourth degree in finite time? I doubt that.

I did not state that. I said that the numbers were computable, where
I use the mathematical sense of computable.

And that means you can compute a number even if you need infinite time.

Rather, you can compute the number to asome (arbitrany finite precision in finite time.

Quote:
Therefore in the mathematical sense each algebraic number is
computable.

Right.

Quote:
(In reality it is not.)

That is why I said exlpicitly *in the mathematical sense*, and when writing
in this group the mathematical sense is generally understood.

Quote:
But even in mathematical sense not
*all* algebraic numbers are computable.

*Each* one is computable. In mathematics that means that *all* are
computable:
for all algebraic numbers there is a turing machine that shows that
number to be computable.
But this does *not* mean:
There is a turing machine that shows that all algebraic numbers are
computable.

Quote:
Should you be able to quote a serious scientist who asserted that the
list of all algebraic numbers was computable? (You would prove this
scientist unserious.)

Cantor? But what it means for a list to be computable is that given
an (arbitrary) natural number n, you can determine the number it points
to in finite time. That is all that it entails for a list to be
computable. And I would think most mathematicians consider that a
list of algebraic numbers is computable. So you apparently think
that mathematicians are not serious scientists. So be it. On the
other hand, you are not a serious mathematician.
--
dik t. winter, cwi, kruislaan 413, 1098 sj amsterdam, nederland, +31205924131
home: bovenover 215, 1025 jn amsterdam, nederland; http://www.cwi.nl/~dik/
Dik T. Winter
Posted: Tue Aug 29, 2006 7:42 pm
Guest
In article <1156689385.395973.61570@74g2000cwt.googlegroups.com> mueckenh@rz.fh-augsburg.de writes:
Quote:
Dik T. Winter schrieb:
In article <virgil-B3927D.12230325082006@news.usenetmonster.com> Virgil <virgil@comcast.net> writes:
....
What I have been able to find was that with indexing of digit WM means
that every digit position can be indexed by a natural number. With
covering WM means that all positions to a certain one can be indexed
by a natural number. What WM is asserting is that when a number can
be totally indexed, it also can be totally covered. Quantifier dislexia
disguised.

Quantifier dyslexia is the assumption that there is a number that
counts all natural numbers, i.e. which is larger than all natural
numbers.

That is not quantifier dyslexia. That is an error by Cantor I already
did comment on. That is, when he writes that to count all natural
numbers you need numbers of the second cardinality (or was it the first?
I disremember what he called aleph-0), he was wrong. To count all natural
numbers you need only natural numbers. On the other hand, the "size"
of the set of natural numbers is not a natural number.

Note, you may critique Cantor's set theory, but that was set theory in
its infancy. It still did contain inconsistencies and errors. Since
that time quite a bit has been developed and corrected.

Quote:
My arguing holds for the unary numbers of my list. If you think not,
then give an example of a finite number n which indexes the digit
position n but does not cover all positions m =< n.

Here is my example: The number 3 = 0.111 in my unary expression indexes
the digit position 3 of any unary number and it covers the digit
positions 1, 2, and 3 of any unary number.

The same can be proven for any finite number n.

Yes, I never ever did argue otherwise. So why do you keep on asserting
that?

Quote:
In 0.111... there are allegedly only finite digit positions. Hence this
proof is valid for every position of this number. Every position can be
indexed, and every position can be covered. This is dictated by logic:

Yes, I never argued otherwise. So why do you keep on asserting that?

Quote:
Position n can be indexed ==> every position m < n can be covered.
Not every position m can be covered ==> not every position n > m can be
indexed.

Right. Because 0.111... has only finite digit positions we have:
(1) *each* digit position can be indexed
(2) *each* digit position can be covered
but not
(3) the number can be covered.
Because (3) would mean that there is a number that covers *all* digits,
and as that number also indexes a digit position, there is a last finite
digit position. But that is not the case. (And this concisely shows
that for finite n, the unary representation *can* be covered.)
You are repeatedly confusing (2) with (3). They are not the same.
--
dik t. winter, cwi, kruislaan 413, 1098 sj amsterdam, nederland, +31205924131
home: bovenover 215, 1025 jn amsterdam, nederland; http://www.cwi.nl/~dik/
Dik T. Winter
Posted: Tue Aug 29, 2006 8:03 pm
Guest
In article <1156842504.966630.131290@h48g2000cwc.googlegroups.com> mueckenh@rz.fh-augsburg.de writes:
Quote:
Dik T. Winter schrieb:

[ talking about {1, 2, 3, ..., w} ]

Quote:
Let us remove omega from that set. What is the resulting cardinality?

Not an actually infinite one, because without omega there are only
finite natural numbers.

But what then?

Quote:
As there is a bijection between that set and the set including omega, their
cardinalities are the same.

No. Without omega there is no actual infinity.

But there is a bijection. And two sets that are in bijection with each
other have the same cardinality. You may think that is a stupid definition,
but nevertheless, it is a definition that works.

Quote:

Your example shows very clear that either both LUBs have to be included
- or none. In my opinion we choose none. But whatever you choose, you
cannot avoid to see the symmetry, can you?

I see the symmetry, I also choose none. And I think I have stated that
already.

Fine. That means there is no actual infinity.

Oh. See above.

Quote:
Wrong. In mathematics the concept of "infinite sum" is not defined,

But if there are infinitely many naturals then the infinite sum is
necessary.

Not at all. Why do we need it?

You should know that the n-th natural number is defined by the sum of
the number n-1 plus 1 (Peano). This can be retraced to the sum of n
1's. What is there to be defined? If there are infinitely many naturals
(and if infinity is a number), then there is at least one infinite sum
of 1's (one from each natural).

Assuming that that sum terminates. Which it does not as there is no last
natural number. Not even set theory makes that a terminating sum. And
this is regardless of whether infinity is a number or not.

Quote:
OK, I kind of understand. I do not state that infinity is a number
aleph_0. There exists a host of infinities. And aleph_0 is the
infinity that gives the equivalence class of sets that are in
bijection with the set of natural numbers; the canonical set with
cardinality infinity.

If aleph_0 > n for n e N, and if there are even numbers x > aleph_0,
then aleph_0 is a number. Cantor stated that. If you do not do so, then
we are in agreement in that point.

You may call it a number, or not. I prefer to call it a cardinal number.
I prefer not to use the word "number" singly, unless there is context
that shows what kind of numbers I am talking about. So I may be talking
about the numbers in the ring Q(sqrt(-3)), or even about the integers in
that ring. Or about the 5-adic numbers, or the Cayley numbers, but
always with context. I think that in his early papers he indeed called
them "Zahlen", but in later papers he did call them "Mächtigkeit". If
you read his papers you may have found that he changes terminology
between papers. Understandable, because it was an early development.
On the other hand, you will see letters by Kronecker where he calls
the elements of Q(sqrt(-3)) or somesuch "Zahlen" (while he already
much earlier tried to remove all non-integers from proofs).

Quote:
Exactly. And in addition, as long as the numbers are finite, ordinal
and cardinal is the same size. That is just why the cardinal cannot be
infinite as long as the ordinal is finite (as expressed by "the
infinite number of finite numbers").

But indeed. If the ordinality of a set if infinite (w or larger), then
so is its cardinality (aleph-0 or larger). On the other hand, if the
cardinality of a set is infinite (aleph-0 or larger), and if it can be
well-ordered, so is its ordinality after well-ordering (w or larger).

As long as the set of natural numbers includes only finite numbers, its
cardinal number is also finite.

What is the cardinality of the set of all finite natural numbers? But
see above. You assert that it is finite. But by the definition, in
that case there is a largest number (say n) in the set, but n+1 is also
a natural number, so we get a contradiction from asserting it to be
finite.
--
dik t. winter, cwi, kruislaan 413, 1098 sj amsterdam, nederland, +31205924131
home: bovenover 215, 1025 jn amsterdam, nederland; http://www.cwi.nl/~dik/
Dik T. Winter
Posted: Tue Aug 29, 2006 8:27 pm
Guest
In article <1156842646.101182.155640@74g2000cwt.googlegroups.com> mueckenh@rz.fh-augsburg.de writes:
Quote:
Dik T. Winter schrieb:
In article <1156585631.775313.153510@h48g2000cwc.googlegroups.com> mueckenh@rz.fh-augsburg.de writes:
....
I don't understand these questions. 1/3 and 1/5 are infinite paths
consisting of infinitely many edges.

You state that you can number the edges. Each edge terminates at a node,
and if 1/3 and 1/5 are in your tree, there must be edges that terminate at
those nodes.

What do you mean with "those nodes"? 1/3 and 1/5 are not nodes but they
are paths.

We can state (if each edge terminates) that at each level we assign the
number at that level to both the path and the terminating node of that
path. If I am wrong here, tell me why I am wrong. So at each level
we have paths with terminating nodes, I meant those terminating nodes
(that we can give the same name as the path that terminates there).

Quote:
In that case you should be able to tell me what the numbers
of those edges are. Or do you now claim that there is *no* edge that
terminates at those nodes? If so, where do the nodes come from? Out of
thin air?

I did already tell you which edges belong to the path 1/3. The nodes
can be enumerated like the edges.

Yes. But you still only have terminating paths. At each level all paths
are terminated by a node. And so 1/3 is not in the tree because there
is no terminating edge and node.

Quote:
As the set of all edges is countable, you
should be able to state that. The problem with your counting method of
edges (count first level 1, next count level 2, etc.) you will already
have exhausted all natural numbers by counting all edges that are at the
end of finite paths.

There are no finite paths and there are no ends at all in my tree.

During your construction process all paths are finite,

There is no construction process. The tree exists like the real numbers
do exist.

Oh, well. As in mathematics the reals require a construction process, so
also your tree requires a construction process. In mathematics the reals
are constructed from the rationals (and I know at least four methods to
do that, that can be shown to give equivalent results). And the rationals
are constructed from the integers. I asked you before, but you never did
reply. Do you know how the rationals are constructed from the integers in
mathematics? More basic, do you know how arithmetic on naturals is defined,
based on the Peano axioms?

Quote:
and there is an
edge that terminates at a node terminating the path. I meant the paths
during the intermediate process of construction.

There is no process of construction. If you have difficulties to
comprehend that: it is the same as with Cantor's list. The tree is
defined once and for all. That's it.

Wrong. But I am not going to explain that again.

Quote:
you think that 0.1 would be represented by a finite path, what should
then be represented by the path 0.1000...?

The same.

By your arguing you would never be able to count the digits of 1/3
because "you will already have exhausted all natural numbers by counting
all edges that are at the end of finite" sequences.

Wrong. To count digits we need only one number for each level.

A set of countably many countable sets is countable.

Right. But 1/3 is not in that set.

Quote:
Do you believe that the set of edges of 1/3 is uncountable?

That is not the set of all edges in the tree.

No. But would you say that the set of all edges of 1/3 and of 1/5 and
of 1/7 were uncountable?

No. Assuming of course that 1/3, 1/5 and 1/7 are in your tree.

All real numbers of the interval [0, 1] are there, some of them even
twice.

Many of them are not. Your tree only contain numbers with a finite binary
expansion. 1/3, 1/5 and 1/7 are not among them.

Quote:
How many paths are required to obtain an
uncountable set of edges, according to your opinion?

Depends quite a bit on a host of questions. In your tree with terminated
edges, also the paths are terminated, so neither becomes uncountable.
But also 1/3 is not in that tree.

You seem to misunderstand the tree. If the diagonal is in Cantor's
list, then 1/3 is in my tree. Can you give a reason why it should not
(other than that then set theory is inconsistent)?

I have explained already many times, but you are not willing to listen.

Quote:
You recently mentioned an interesting aspect: The algebraic numbers,
i.e., the polynoms are countable, because they are finite. And,
therefore, you wanted only to count the finite segments of paths in my
tree. I oppose, unless you agree that the 1's in 0.111... also are
uncountable. You see, the problem is the same: We can count finite
segment but not infinity.

You are using a pretty strange terminology. You can count the algebraic
numbers just because the polynomials remain finite (but there are
infinitely many of them). You can count the finite paths because they
are finite (but there are infinitely many of them). You can count
the digits because each digit position is finite (but there are infinitely
many of them). What inconsistency?

Quote:
Either you agree that all the edges of my tree are countable or you
agree that Cantor's diagonal is uncountable. Or you state at least how
many infinite path in my tree you would consider to have completely
countable edges.

This question makes not sense to me.
--
dik t. winter, cwi, kruislaan 413, 1098 sj amsterdam, nederland, +31205924131
home: bovenover 215, 1025 jn amsterdam, nederland; http://www.cwi.nl/~dik/
David R Tribble
Posted: Tue Aug 29, 2006 8:44 pm
Guest
Tony Orlow wrote:
Quote:
Any finite number of bit positions produces a finite set of strings.

Any countably infinite set of bit positions produces an uncountable set of
strings.


Tony Orlow wrote:
Quote:
Which explains why the reals are uncountable (when represented as
infinite binary fractions in [0,1)).


Tony Orlow wrote:
Quote:
Yes, ala Cantor's second proof of uncountability.


David R Tribble wrote:
Quote:
But it does not explain your claim that the naturals are uncountable
when represented as finite bitstrings. It's pretty straightfoward to
show that a countable number of bits produces a countable number
of bitstrings. There is no "in-between" cardinality.


Tony Orlow wrote:
Quote:
You just contradicted yourself.

You agree that [me] "Any countably infinite set of bit positions
produces an uncountable set of strings", right? That's what [you]
"explains why the reals are uncountable (when represented as infinite
binary fractions in [0,1))"?But, [you] "a countable number of bits
produces a countable number of bitstrings"? Is a countably infinite
number of bits countable or not? If so, then does a countably infinite
number of bit positions produce a countable, or an uncountable, set of
strings?

A slight misunderstanding, so I'll rephrase it (even though you've
heard it all before).

If every bitstring contains a finite number of bits, the set of all
finite bitstrings (or binary naturals, or finite-length binary tree
paths) is countably infinite.

If the bitstrings are infinite, containing a countably infinite number
of bits, the set of all infinite bitstrings (or nonterminating binary
real fractions, or nonterminating infinite binary tree paths) is
uncountably infinite.


David R Tribble wrote:
Quote:
It also flies in the face of your statements about infinite binary
trees. If each node is numbered with a natural (being the finite
bitstring of the left/right paths traversed from the root to the node),
then the nodes, and thus the naturals, are obviously countable.

On the other hand, you don't understand that the infinite paths in
the tree (the ones that don't have a terminating node) are uncountable
and correspond directly to your infinite bitstrings and to the real
binary fractions in [0,1).


Tony Orlow wrote:
Quote:
I'll wait for your response on the above, since you're still not ready
for the answer you've already heard for this. Please don't snip it. It's
a good question, and a prime example of standard issues.
Dik T. Winter
Posted: Tue Aug 29, 2006 8:57 pm
Guest
In article <1156842732.043353.163480@74g2000cwt.googlegroups.com> mueckenh@rz.fh-augsburg.de writes:
Quote:
Dik T. Winter schrieb:
....
Cantor states (analogously) that *all stairs exist*, that the width of
all ot them is L, but that none of them has hight L. Width [0, 1] and
height [0, 1).

A quote please. But indeed, the width of all of them is L, but there is
none of them with width L. And the heighth of all of them is L, but there
is none of them with heighth L. So width [0,1] and heighth [0,1]. That
is, if you define both as the smallest box containing the completed stair.
If you define both as the largest numbers that can be obtained, you get
width [0,1) and heighth [0,1).

You are trying to make it difficult, using UTF-8. But this one takes the
cake.
Quote:
I agree with you. But Cantor said (Werke, p. 409): "So stellt uns
beispielsweise eine veränderliche Größe x, die nacheinander die
verschiedenen endlichen ganzen Zahlwerte 1, 2, 3, ..., v, ...
anzunehmen hat, ein potentiales Unendliches vor, wogegen die durch ein
Gesetz begrifflich durchaus bestimmte Menge (=EF=81=AE) aller ganzen
If "=EF=81=AE" is UTF-8, the Unicode character is U+F06E, which is in the

private area of characters. I have no idea what that symbol stands for,
so I will modify it to N.
Quote:
endlichen Zahlen N das einfachste Beispiel eines aktual-unendlichen
Quantums darbietet.

Again translated (why do you post so much German in an English speaking
newsgroup while you should know that most readers are not able to read
German?):
Cantor: So while a changing quantity x that successively takes the
various values of finite numbers 1, 2, 3, ..., v, ... , is a
potential infinite, on the other hand, a through the axioms completely
determined set (N) of all integral finite number is an example of an
actually finite quantity.
Nice that you found the quote I have alluded to, and that you did deny
of existing, but that I could not find back.

What Cantor is stating here (and I did already indicate that in an
earlier response), is, translated to current set theory:
The set N is potentially infinite, the size of N is actually infinite.
(In current terminology a set is not a quantity.)

Quote:
And I am arguing against this actual understanding of infinity.

Try to argue with something beyond Cantor.
--
dik t. winter, cwi, kruislaan 413, 1098 sj amsterdam, nederland, +31205924131
home: bovenover 215, 1025 jn amsterdam, nederland; http://www.cwi.nl/~dik/
Dik T. Winter
Posted: Tue Aug 29, 2006 9:00 pm
Guest
In article <1156842898.805375.169610@h48g2000cwc.googlegroups.com> mueckenh@rz.fh-augsburg.de writes:
Quote:
Dik T. Winter schrieb:
....
You gave an example how a number of the form 0,111...1 with n digits
indexes the n-th digit but does not cover all digits with m =<n ???

No, because that does not exist.

How then can you believe and assert that the number 0.111... which has
*only finitely indexable positions* could be completely indexed but not
covered.

Because there are infinitely many finitely indexable positions. Do you
see the way in which the first number you give "0.111...1" differs from
the second number you give "0.111..."?
--
dik t. winter, cwi, kruislaan 413, 1098 sj amsterdam, nederland, +31205924131
home: bovenover 215, 1025 jn amsterdam, nederland; http://www.cwi.nl/~dik/
Dik T. Winter
Posted: Tue Aug 29, 2006 9:18 pm
Guest
In article <1156843043.617422.7230@i3g2000cwc.googlegroups.com> mueckenh@rz.fh-augsburg.de writes:
Quote:
Dik T. Winter schrieb:
In article <1156689126.335154.133150@h48g2000cwc.googlegroups.com> muecke=
nh@rz.fh-augsburg.de writes:
Dik T. Winter schrieb:
The first part of his first proof shows that a complete ordered=
field
has cardinality larger than the natural numbers. In his proof =
he did
not rely an any properties of the reals other than that they fo=
rm a
complete ordered field (he uses reals to exemplify).
...
Note what I wrote: "in his proof he did not rely on any properties of
the reals other than that they form a complete ordered field". What
other properties of the reals did he use?

He had no field and he used no filed. What is a field without the
axioms of the field? Nothing. Cantor disliked axioms if he did not hate
them. His only concern were numbers, numbers, numbers and their
*reality*. No fields and no axioms.

Perhaps. I thought we were discussing current set theory. And not what
in some time long ago was et theory. He may not have liked them, but in
current terminology "the first proof shows that a complete ordered field
has cardinality larger than the natural numbers".

In the terminology of the next century it may show even other things,
more general perhaps, with even more insight. I was discussing what
Cantor did. You were accusing me that I had not understood or misquoted
him.

Please reread the history of this discussion. I did not accuse you of
anything in this instance, only on misreading what I wrote. At some stage
I responded to somebody else (I think it was Virgil) that in the first proof
Cantor showed that complete ordered fields were not countable. You accused
me of misinterpretation.

The only case where I accused you of misquoting was when you left out
the first sentence of a paragraph that would be revealing. But, see
below.

Quote:
Aus dem in =3DA7 2 Bewiesenen folgt n=3DE4mlich ohne weiteres, da=3DDF

Quoting again only in part. I will quote the translation I gave, with
annotation of the complete paragraph, not only the part you like to quote:
In the article, titled: "Über eine Eigenschaft des Ombegriffs aller
reellen algebraischen Zahlen (Journ. Math. Bd. 77, S. 258) [hier
S. 115], can for the first time be found a proof of the theorem
that there are infinite sets that are not in bijection with the set of
natural numbers 1, 2, 3, ..., v, ..., or, as I say in general, do not
have the same cardinality as the natural numbers 1, 2, 3, ..., v, ... .
So apparently he is thinking that his first article proves the theorem
that there are sets that are not in bijection with the natural numbers.
Which is true.

Of course: The set of the reals and the set of the transcendental
numbers are such sets. So he has the right to speak generally about
"sets". Which mathematician would not like to generalize his theorems?

But note what he now claims the theorem actually *is*.

Quote:
From what has been proven in section 2 follows that e.g. the
set of real numbers in an arbitrary interval can not be put in
a sequence w_1, w_2, w_3, ..., w_v, ... .
So he is now thinking that that proof was just an example for such a set.
Which it is. The "beispielsweise" is telling.
It is however possible to construct a much simpler proof for
that theorem that is independent from the observation of irrational
numbers.

Independent of the *necessary use* of irrational numbers.

Where in the German do you find "necessary use"? "ein viel einfacherer
Beweis liefern, der unäbhangig fon der Betrachtung der Irrationalzahlen
ist."

Quote:
And the "that theorem" (in German "jenem Satze") can, in my opinion only
refer to the theorem mentioned in the first sentence in this paragraph.

That theorem the proof of which depends on irrational numbers.

Nope. That theorem is the theorem he stated in extenso in the first
sentence.
--
dik t. winter, cwi, kruislaan 413, 1098 sj amsterdam, nederland, +31205924131
home: bovenover 215, 1025 jn amsterdam, nederland; http://www.cwi.nl/~dik/
David R Tribble
Posted: Wed Aug 30, 2006 5:14 pm
Guest
Quote:
But since no natural requires an infinite bit string, that is irrelevant.

Tony Orlow schrieb:
Quote:
If no natural requires an infinite bit string, even the very largest,
and all bit positions are included in it, then no infinite set of bit
positions is required.


mueckenh wrote:
Quote:
Tony, please drop the "very largest". The rest is ok. If no natural
requires an infinite set then all naturals together do not require an
infinite set. If the contrary is asserted (and if infinity is a number
larger than any finite number), then we may ask which natural is the
first such that all of its predecessors require an infinite number of
bit positions.

There is no natural with an infinite number of bits. Every natural
is a finite binary string. There is no natural with an infinite
number of predecessors. Every natural has an infinite number
of successors, however. (Which agrees with what you just said
to Tony about there being no "very largest" natural.)

It is truly breathtaking that there are people who cannot grasp
the elementary concept that if there is no largest finite natural
then there must be an infinite number of them. Even children
understand that there is no biggest number (because you can
always add one to any number you think is the largest), and
therefore "numbers never end" (to quote my six-year old
daughter).
 
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