This month's riddle comes from Yuval Filmus and Avinoam Braverman.
Suppose you want to find the factors of a number,
Because
We are left with a set of (
The question is: what does it converge to, when
To be mathematically precise, we are asking here about convergence in the
upper Vietoris topology. The meaning of this
is as follows: The limit, For brevity, we refer to "convergence" and to "limit" without specifying the topological space each time. NB - We will only accept this month solutions in which the description of the limit set is exact. As a bonus question, you are welcomed to consider also what is the limit, if we repeat the filter operation for a second time: instead of looking at local minima, we look in the bonus question only at local minima of local minima. |
## List of solvers:Itsik Horovitz (31 October 20:00) |

Elegant and original solutions can be submitted to
the puzzlemaster at __riddlesbrand.scso.com__.
Names of solvers will be posted on this page. Notify if you don't want
your name to be mentioned.

The solution will be published at the end of the month.

Enjoy!