Re: The set of necessary FISONs

Le 03/02/2025 à 16:11, crank Wolfang Mückenheim aka WM a écrit :

German A(n), or English F(n)

I'm quite sure A(n) is not a German expression, neither is F(n) an English one.

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

Anyone able to claim such a fallacy shouldn't be allowed to be put in front of students, in any country.