Sujet : Re: How many different unit fractions are lessorequal than all unit fractions? (repleteness)
De : james.g.burns (at) *nospam* att.net (Jim Burns)
Groupes : sci.mathDate : 19. Sep 2024, 18:29:14
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <4d1b9bf2-7f08-4695-9f00-b5e4a4fa2eb3@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
User-Agent : Mozilla Thunderbird
On 9/19/2024 12:29 AM, Ross Finlayson wrote:
On 09/18/2024 01:51 PM, Ross Finlayson wrote:
On 09/18/2024 12:37 PM, Chris M. Thomasson wrote:
On 9/17/2024 7:58 PM, Ross Finlayson wrote:
On 09/17/2024 01:11 PM, Jim Burns wrote:
Unlike ℕ and ℤ, ℚ and ℝ do not 'next'.
[...]
>
Put pencil to paper and draw a straight line,
each of the points were encountered in order.
No matter how fine it's sliced, ....
>
Sometimes called "Hilbert's Postulate of Continuity".
>
Which he says is required, ....
In a straight line or in a straight anything,
its order '<' is
⎛ connected (x≠y ⇒ x<y ∨ y<x)
⎜ transitive (x<y ∧ y<z ⇒ x<z)
⎜ asymmetric (x<y ⇒ y≮x)
⎝ irreflexive (x≮x)
That states that
each of the points are encountered in order,
but
it leaves unstated what points are there,
and whether they are points which 'next'.
ℝ is what.we.mean.by the continuum because
ℚ is gapless (ℚ does not 'next')
⎛ ¬∃q,q″ ∈ ℚ: q < q″ ∧
⎝ ¬∃q′ ∈ ℚ: q < q′ < q″
and ℝ completes ℚ
⎛ ¬∃S ⊆ ℚ: {} ≠ S ᵉᵃᶜʰ<ᵉᵃᶜʰ ℚ\S ≠ {} ∧
⎝ ¬∃r ∈ ℝ\ℚ: S ᵉᵃᶜʰ< r <ᵉᵃᶜʰ ℚ\S
such that
crossing ℝ×ℝ.curves intersect,
either in ℚ or in ℝ\ℚ
We have found that it is necessary and sufficient
for crossing curves to intersect
in order to serve as what.we.mean.by continuum.