### First section

Another post to see how slug works. $\KaTeX$ inline and display equations.

#### First subsection

\[ f(n) = \sum_{k = 1}^\infty g(k) \]

#### Second subsection

$$\Omega = \bigcap_n A_n,$$

### Second section

Here’s the sources.

#### subsection 2.1

```
<div>
\[ f(n) = \sum_{k = 1}^\infty g(k) \]
</div>
```

#### subsection 2.2

```
$$\Omega = \bigcap_n A_n,$$
```