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Topic: ZFC and God
Replies: 45   Last Post: Apr 18, 2013 3:47 AM

 Messages: [ Previous | Next ]
 mueckenh@rz.fh-augsburg.de Posts: 18,076 Registered: 1/29/05
Re: ZFC and God
Posted: Jan 22, 2013 3:28 AM

On 21 Jan., 19:07, Zuhair <zaljo...@gmail.com> wrote:

> Doesn't that say that mathematics following ZFC is only grounded in
> Mythology driven principles!
>
> Doesn't that mean that ZFC based mathematics is too imaginary that
> even if consistent still it is based and rooted in fantasy that cannot
> really meet reality!

ZFC is not consistent unless inconsistencies are defined to be no
inconsistencies, distinctions need not be distinguishable,
incomletenesses need not be incomplete, and so on.

Consider, for instance, all terminating binary fractions b_n
0.0
0.1
0.00
0.01
0.10
0.11
0.000
where some numbers are represented twice (in fact each one appears
infinitely often). Constructing the diagonal d we find that d differs
from *every* b_n *at a finite place*.

Since the above list is complete, which is possible because all
terminating fractions, as a subset of all fractions, are countable, it
is impossible that the diagonal differs from all entries b_n at a
finite place. If this was possible, the list would have a gap, namely
a finite initial segment of d. That means, the diagonal up to every
bit can be found in the list. And after every finite place there is
nothing that could distinguish two numbers.

Therefore the diagonal does not increase the cardinal number of the
listed entries b_n.

The diagonal may be infinitely long. But what does that mean? Every
given number of bits is surpassed. But the same holds for the entries
of the list. The only difference could be a bit of the diagonal that
has no finite index. But such bits are not part of mathematics and of
Cantor's argument.

Regards, WM