Re: The set of necessary FISONs

On 04.02.2025 01:39, Richard Damon wrote:

On 2/3/25 10:11 AM, WM wrote:

On 02.02.2025 21:11, Richard Damon wrote:
>

Since I don't recall you actually DEFINING what A(n) means, any assumption about it would be unwarranted.

>
German A(n), or English F(n) is the FISON {1, 2, 3, ..., n}.
The assumption is that U(F(n)) = ℕ.

 Then why did you change your notation.

My mistake.

By induction we prove that every F(n) can be removed without changing the union. Therefore the assumption leads to { } = ℕ. Therefore the assumption is wrong.

 No, you prove that ANY FISON can be removed, not that ALL can be.

Peano constructs ℕ by induction, all natural numbers. To deconstruct it is not possible?
Regards, WM