Sujet : Re: Incompleteness of Cantor's enumeration of the rational numbers
De : james.g.burns (at) *nospam* att.net (Jim Burns)
Groupes : sci.mathDate : 29. Nov 2024, 19:08:59
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <0b2e9a84-f5b3-4f02-8f78-7781da9175af@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
User-Agent : Mozilla Thunderbird
On 11/27/2024 4:33 PM, WM wrote:
On 27.11.2024 20:47, Jim Burns wrote:
Finite cardinals can change by 1
The cardinal |ℕᶠⁱⁿ| cannot change by 1
>
Small wonder.
Fuzzy properties like "many" cannot change by 1.
⎛ ℕᶠⁱⁿ is the set of finite cardinals.
⎜ Bob is not a cardinal.
⎜
⎜ ∀ᶜᵃʳᵈξ: ξ ∈ ℕᶠⁱⁿ ⇔
⎜ ⟦0,ξ⦆∪{Bob} ≠ ⟦0,ξ⟧ ∧ |⟦0,ξ⦆∪{Bob}| ≠ |⟦0,ξ⟧|
⎜
⎝ ℕᶠⁱⁿ∪{Bob} ≠ ℕᶠⁱⁿ ∧ |ℕᶠⁱⁿ∪{Bob}| = |ℕᶠⁱⁿ|
Yes,
the sets can change membership by 1
However,
the cardinalities of those sets cannot change by 1
>
This proves that cardinality is a fuzzy property.
The whole ℕᶠⁱⁿ×ℕᶠⁱⁿ matrix can fit in
its first column ℕᶠⁱⁿ×{0}
⎛ ℕᶠⁱⁿ×ℕᶠⁱⁿ ⇉ ℕᶠⁱⁿ×{0} ⇉ ℕᶠⁱⁿ×ℕᶠⁱⁿ
⎜ ⟨i,j⟩ ↦ ⟨n,0⟩ ↦ ⟨i,j⟩
⎜ n = (i+j)⋅(i+j+1)/2+j
⎜ (i+j) = ⌊(2⋅n+¼)¹ᐟ²-½⌋
⎜ j = n-(i+j)⋅((i+j)+1)/2
⎝ i = (i+j)-j
The fuzzy cardinality property
predicts that it can.
Your crisp cardinoid property
predicts otherwise
and is incorrect.
After all the swaps
(of which no swap is a change in cardinality)
what remains is a proper subset
(which is not a change in cardinality).
'Bye, Bob.
This proves that cardinality is a fuzzy property.
⎛
⎜ An hungry Fox with fierce attack
⎜ Sprang on a Vine, but tumbled back,
⎜ Nor could attain the point in view,
⎜ So near the sky the bunches grew.
⎜ As he went off, "They're scurvy stuff,"
⎜ Says he, "and not half ripe enough--
⎜ And I 've more rev'rence for my tripes
⎜ Than to torment them with the gripes."
⎜ For those this tale is very pat
⎜ Who lessen what they can't come at.
⎝
http://mythfolklore.net/aesopica/phaedrus/43.htm