An Interesting Set Problem: Proving Closure Property

Discover an intriguing set problem as we prove closure properties step by step.
A problem from Math Stack Exchange.
#manim #mathproof #mathematics #algebra
Corrections:
0:00 a ∈ S\{0}, then 1/a ∈ S\{0}
0:55 "a ∈ S, then a² ∈ S" don't need to prove for a = 0 or -1, hence 1/(a+1), 1/(a² +a) and 1/a² do exist.

[@gregevgeni1864]

Thanks!