Sujet : Re: Contradiction of bijections as a measure for infinite sets
De : james.g.burns (at) *nospam* att.net (Jim Burns)
Groupes : sci.mathDate : 05. Apr 2024, 20:03:30
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <373b543f-be44-4441-b9d3-9fdb44287e95@att.net>
References : 1 2 3 4 5 6 7 8 9 10 11
User-Agent : Mozilla Thunderbird
On 4/5/2024 5:06 AM, WM wrote:
Le 04/04/2024 à 17:03, Jim Burns a écrit :
always ⟦0,m+1⟧ ≠ ⟦0,ω⟧
I define a Mückenheim set such that,
for any set, either
all injections are onto, or
all injections are not.onto.
Mückenheim.set M ⟺
∀S: ∀f:M⇉S=f(M) ∨ ∀g:M⇉S≠g(M)
not.Mückenheim.set M ⟺
∃S: ∃f:M⇉S≠f(M) ∧ ∃g:M⇉S=g(M)
Define ⟦0,ω⦆ = lub{Mückenheim ⟦0,m⟧}
The difference between ⟦0,m+1⟧ and ⟦0,ω⟧ is
how large?
Larger than any Mückenheim ⟦0,m⟧
thus
not a Mückenheim.set
thus
the same as
between ⟦0,m⟧ and ⟦0,ω⟧ and
between ⟦0,m+2⟧ and ⟦0,ω⟧.
Is it ω for every m?
∀k,m ∈ ⟦0,ω⦆: k+m ∈ ⟦0,ω⦆
So, yes.
Then what are the ordinals between m and ω?
They are the elements of ⦅m,ω⦆
They are dark.
Visibleᵂᴹ or darkᵂᴹ, always ⟦0,m+1⟧ ≠ ⟦0,ω⟧
On the other hand
no ordinal fits between ℕ and ω.
ℕ = ⟦0,ω⦆
So, we agree on something.
Dark ordinals reach till ω.
Agreed?
⟦0,ξ⟧ which reaches 'til ω both
is a Mückenheim.set and is not a Mückenheim.set.
Agreed?