@RRL @XanderHenderson @JoséCarlosSantos @YuiToCheng: This post is implicitly using a nonsensical definition of exponentiation, which doesn't even obey the LaTeX syntax!!
Let $S$ be a subset of a topological space. I want to prove or disprove the following claim:
$\left(\overline{\left( \overline{S} \right)^\circ}\right)^\circ=\left( \overline{S} \right)^\circ$
Setting $A=\left( \overline{S} \right)^\circ$, we have:
$A=\left( \overline{A} \right)^\circ$.
I kno...