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 : 08. Jan 2025, 00:50:02
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <417ff6da-86ee-4b3a-b07a-9c6a8eb31368@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 26
User-Agent : Mozilla Thunderbird
On 1/7/2025 4:13 AM, WM wrote:
On 06.01.2025 23:43, Jim Burns wrote:
On 1/5/2025 1:14 PM, WM wrote:
ℕ cannot be covered by FISONs,
neither by many nor by their union.
If ℕ could be covered by FISONs
then one would be sufficient.
>
ℕ is the set of finite.ordinals.
ℕ holds each finite ordinal.
ℕ holds only finite.ordinals.
A finite.ordinal k = ⟦0,k⦆ is an ordinal which
is smaller.than fuller.by.one sets,
that is, k for which #⟦0,k⦆ < #⟦0,k+1⦆
ℕ = ⦃finite⦄ is the set of ordinals which
are smaller.than fuller.by.one sets.
|ℕ| is by definition
the smallest transfinite number,
|ℕ| = #ℕ is by definition
the smallest transfinite cardinal, that is,
the smallest cardinal #Y of any set Y which
is NOT smaller.than.fuller.by.one sets.
ω = ⟦0,ω⦆ is by definition
is NOT smaller.than fuller.by.one sets (transfinite) and
IS the first among the (well.ordered) ordinals which are
NOT smaller.than.fuller.by.one sets (the transfinites).
¬(#⟦0,ω⦆ < #⟦0,ω+1⦆)
¬(#⟦0,ξ⦆ < #⟦0,ξ+1⦆) ⇒ ω ≤ ξ
∀ᵒʳᵈj,k < ω:
#⟦0,j⦆ = #⟦0,k⦆ ⇔ ⟦0,j⦆ = ⟦0,k⦆
#⟦0,ω⦆ = #⟦0,ω+1⦆ ∧ ⟦0,ω⦆ ≠ ⟦0,ω+1⦆
The cardinal:ordinal distinction
-- which does not matter in the finite domain
matters in the infinite domain.