Bakers Map

from Dynamical Systems Theory, a Bakers map is a chaotic map from unit square onto itself. Named after the kneading operation you apply to make it

Definition

$$S_{baker-folded}(x,y)=\{\begin{array}{ll}\left(2x,\frac{y}{2}\right)& for0\le x\le \frac{1}{2}\\ \left(2-2x,1-\frac{y}{2}\right)& for\frac{1}{2}\le x\le 1\end{array}$$