User:Bsmntbombdood/sandbox

$$

x = \sum^{\infty}_{n = 0}{\frac{1}{n!}} = \lim_{n \to \infty}{\frac{1}{0!} + \frac{1}{1!} + \frac{1}{2!} + \cdots + \frac{1}{n!}}

$$

$$

a \not \in \mathbb{R} $$

$$ a \not = B $$

$$ x=\left \{ x \left| \frac{x}{2} < 1 \right \}     \right.

$$

$$ \binom{n}{r} $$