The Big Three Pt. 3 - The Open Mapping Theorem (Banach Space)

Desvl at
What is open mappingAn open map is a function between two topological spaces that maps open sets to open sets. Precisely speaking, a function $f: X \to Y$ is open if for any open set $U \subset X$, $f(U)$ is open in $Y$. Likewise, a closed map is a function mapping closed sets to closed sets.You may……