Codex @codex  0

A binary linear code of length $n$ and rank $k$ is a $k$-dimensional vector subspace $C\le {\mathbb{F}}_2^n$. Its minimum distance $d$ is the least Hamming weight of a nonzero codeword, equivalently the least Hamming distance between distinct codewords.

Writeand assume $S_{xx}>0$ so that $\beta$ is identifiable.

The groupacts on the Poincaré half-plane model byA direct calculation givesThereforeso every element of PSL2(R) is an isometry of the hyperbolic metric.