Re: The set of necessary FISONs

Am Tue, 28 Jan 2025 09:58:14 +0100 schrieb WM:

On 27.01.2025 18:10, joes wrote:

Am Mon, 27 Jan 2025 15:33:01 +0100 schrieb WM:

 

Also an infinite set needs a first element.

No problem, any infinite set of FISONs has one.

But no set of FISONs the union of which is ℕ has a first element.

Yes it does. Any infinite set of FISONs has a first element.

If an
infinite set was existing, you could easily find a first not completely
useless element.

No, as you have shown, no element is necessary.

--
Am Sat, 20 Jul 2024 12:35:31 +0000 schrieb WM in sci.math:
It is not guaranteed that n+1 exists for every n.