On 9/8/2021 12:21 PM, WM wrote:
> Jim Burns schrieb
> am Montag, 6. September 2021 um 21:33:27 UTC+2:
>> On 9/6/2021 12:17 PM, WM wrote:
>>> All transpositions are allowed.
>>> They will not change the bijection, if a bijection exists.
>>
>> You have returned to Hilbert's Hotel.
>
> Note that Hilbert's hotel will accommodate the new giest
> in romm number 1.
Hilbert's Hotel is infinite.
Bijections exist between its rooms and proper subsets of
its rooms.
The same (infinite) roster of guests can either be accommodated
one to each room or accommodated one to every prime-numbered room,
leaving composite-numbered rooms empty.
How can finite beings know "infinite" facts like this?
We can partially describe one of infinitely-many guests or rooms,
and reason from that description to further claims about the
same infinitely-many guests or rooms.
Our reasoning preserves the truth of the original description of
a guest or of a room in the further claims about that guest or that
room, whether or not which guest or room is referred to is part of
the description.
>> The problem with your rule
>> (and it is only your (WM's) rule, not logic's)
>
> This is logic:
> Before (with respect to the well-order of the natural numbers)
> all fractions have been indexed,
> all unit intervals must have been indexed.
Consider the collection
{ k | {0,...,k} is doubly-well-ordered }
{0,...,k} is doubly-well-ordered iff
each non-empty subset of {0,...,k} contains a first and
a last, including {0,...,k}.
0 is first of and k is last of {0,...,k}.
{ k | {0,...,k} is doubly-well-ordered }
is NOT doubly-well-ordered.
For each j in { k | {0,...,k} is doubly-well-ordered },
j+1 is in { k | {0,...,k} is doubly-well-ordered }.
Thus, { k | {0,...,k} is doubly-well-ordered } does not
have a last and so is not doubly-well-ordered.
----
Before all fractions have been indexed,
there is some index m such that {0,...,m}
contains all the indexes used so far.
Let Firsts = { first index of a rational in (n,n+1] }
Firsts is NOT doubly-well-ordered,
because it does not contain a last first index.
If this is possible
|
| Before all fractions have been indexed,
| all unit intervals must have been indexed.
|
then Firsts is a subset of doubly-well-ordered {0,...,m}
for some m.
If it were a subset, it would have a last.
It doesn't have a last.
Contradiction.
| Before all fractions have been indexed,
| all unit intervals must have been indexed.
|
is impossible.
> This all must happen with finite distinguishable indices.
No.
For any m, Firsts cannot be a subset of {0,...,m}.
> Therefore it is impossible that the completion of intervals
> is simultaneous to the completion of fractions.
All the firsts-in-an-interval do not have a completing index
If you describe them that way, you will describe them incorrectly.
All the rationals do not have a completing index
If you describe them that way, you will describe them incorrectly.
It is impossible for these non-existent indexes to be
simultaneous. That isn't because they're dark. It's because
they're non-existent.
> According to logic the fractions within any interval (n-1, n]
> will be indexed *after* n/1. This holds for all intervals,
> whether or not there is a last one. All existing naturals are
> indexing all existing intervals.
> More is not possible, as soon as aleph_0 intervals have been
> indexed, i.e., as soon as all existing naturals have been issued.
More is not necessary.
As soon as aleph_0 intervals have been indexed, all
finitely-indexed rationals have been indexed.
That's all of them.
We know that's all of them because,
if
steppable {0,...,j} exists with adjacent h, i = h+1, and
steppable {0,...,k} exists with adjacent h, i = h+1,
then
steppable {0,...,j+k} exists with adjacent h, i = h+1, and
steppable {0,...,j*k} exists with adjacent h, i = h+1, and
...
steppable {0,...,j+(j+k-1)*(j+k-2)/2} exists
with adjacent h, i = h+1.