Re: The set of necessary FISONs

On 01.02.2025 14:16, joes wrote:

Am Sat, 01 Feb 2025 13:24:31 +0100 schrieb WM:

On 31.01.2025 15:46, Richard Damon wrote:

It works that way: When n belongs to ℕ, then n+1 belongs to ℕ.
And it works also thos way:
When n can be deleted, then n+1 can be deleted. Nothing remains.

It works this way: If n can be removed, n AND n+1 can be removed.
But it doesn’t work this way: „If n can be left out, all n can be.”

Which one cannot be removed?
What is the difference between adding and subtracting?
Regards, WM