Kuratowski's Closure-Complement Problem/Complement of Interior of Closure of Interior

Theorem
The complement of the interior of the closure of the interior of $A$ in $\R$ is given by:


 * Kuratowski-Closure-Complement-Theorem-CompIntClosInt.png

Proof
From Kuratowski's Closure-Complement Problem: Interior of Closure of Interior:

The result follows by inspection.