Sujet : Re: Incompleteness of Cantor's enumeration of the rational numbers (extra-ordinary)
De : james.g.burns (at) *nospam* att.net (Jim Burns)
Groupes : sci.mathDate : 13. Jan 2025, 18:06:44
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <e8fcb812-242f-4563-bdeb-ea3221b0aaf2@att.net>
References : 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
User-Agent : Mozilla Thunderbird
On 1/13/2025 7:48 AM, WM wrote:
On 13.01.2025 05:51, Moebius wrote:
Es gilt dann also |ℕ|/n = |ℕ|.
>
Wrong. |ℕ| is a fixed number.
By 'fixed', you mean that #ℕ > #(ℕ\{0})
However,
ℕ is the set of all 'fixed' (finite) ordinals.
⎛ Assume ℕ is 'fixed'.
⎜
⎜ A 'fixed' ordinal ⟦0,𝔑⦆ the size of ℕ exists.
⎜ #⟦0,𝔑⦆ = #ℕ
⎜
⎜ ⟦0,𝔑+1⦆ is 'fixed', too.
⎜ ⟦0,𝔑+1⦆ ⊆ ℕ
⎜ #⟦0,𝔑+1⦆ ≤ #ℕ
⎜ #ℕ = #⟦0,𝔑⦆ < #⟦0,𝔑+1⦆ ≤ #ℕ
⎜ #ℕ < #ℕ
⎝ Contradiction.
Therefore,
ℕ is not 'fixed'.