i^2 = 1 \Leftrightarrow e^{\pi i} + 1 = 0
f(\boldsymbol x) = {1\over 2}(\mathbf{w}^T\boldsymbol{x}-y)^2+\sum_{i=1}^K w_i^2
2H_2 + O_2 \xrightarrow{n,m}2H_2O
\vec{F}_g=-F\frac{m_1 m_2}{r^2} \vec{e}_r
\sideset{_\theta^\sigma}{_\alpha^\beta} X