Sujet : Re: Replacement of Cardinality
De : james.g.burns (at) *nospam* att.net (Jim Burns)
Groupes : sci.mathDate : 04. Aug 2024, 18:59:10
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <60b4e96f-8711-455b-b8ed-755abf3ad543@att.net>
References : 1 2 3 4 5 6 7 8 9 10 11
User-Agent : Mozilla Thunderbird
On 8/4/2024 11:44 AM, WM wrote:
Le 03/08/2024 à 19:42, joes a écrit :
[...]
>
The reversed quantification is nonsense
...because from ∀x∃u to ∃u∀x is unreliable.
From ∃u∀x to ∀x∃u is reliable.
From ∃u∃x to ∃x∃u is reliable.
From ∀u∀x to ∀x∀u is reliable.
However,
from ∀x∃u to ∃u∀x is unreliable.
In some cases,
from ∀x∃u to ∃u∀x is not.only.unreliable,
it is incorrect.
'<' is a case in which it is incorrect.
From ∀x∃u≠x:x<u to ¬∃u∀x≠u:x<u is reliable.
because
ℵ₀ unit fractions need ℵ₀*2^ℵ₀ points above zero.
Sets ordered so that all non.{}.subsets are 2.ended
are finite sets.
Sets ordered so that any non.{}.subset is non.2.ended
are infinite sets.
For each unit.fraction,
the set of unit.fractions below it is non.2.ended.
It is an infinite set.
For each unit.fraction,
each non.{}.subset of unit.fractions above it is 2.ended.
The unit.fractions above it are finitely.many.