User:Anghel/Sandbox

Theorem
Let $f : \closedint 0 1 \to \R^2$ be a Jordan curve.

Let $\Img \gamma$ denote the image of $\gamma$, $\Int \gamma$ denote the interior of $\gamma$, and $\Ext \gamma$ denote the exterior of $\gamma$.

Let $\mathbb S^1$ denote the unit circle, $$ Definition:Open Ball