Re: The set of necessary FISONs

On 22.02.2025 11:45, joes wrote:

Am Thu, 20 Feb 2025 11:29:26 +0100 schrieb WM:

On 19.02.2025 18:19, joes wrote:

If you think UF = X != N, then you need to accept U{} = X.

No. I don't know the relation between a FISON and X.

X is clearly an inductive set, like N.

If X is defined as the true UF (I had overlooked that), then we cannot apply
|X \ {1, 2, 3, ..., n}| = ℵo
and then U{} = X does not follow.
X is a FISON like every finite union of FISONs.
We know that although we cannot determine X.
Regards, WM