A simple equation for a line in $\mathbb{R}^2$:

\[ y = mx + b \]

Again, but with dollar signs:

$$ y = mx + b $$

# Regarding $\vec g$ and its effects

Math in a heading

~~~~ {.haskell}
f x = length $ tail x
~~~~

$x + 1$

$e_{ik}$ in the statement the theorem about $V_k$

<!-- Local Variables: -->
<!-- markdown-enable-math: t -->
<!-- End: -->