\widetilde{ab}
\overleftarrow{ba}
\overline{ab}
\overbrace{ab}
\sqrt{ab}
f'
x^{k}
\lim_{a \rightarrow b}
\begin{bmatrix}a & b \\c & d \end{bmatrix}
\big(a\big)
\int_a^b x
\sum_a^b x
\prod_a^b x
\bigcap_a^b x
\bigvee_a^b x
\bigotimes
\widehat{ab}
\overrightarrow{ab}
\underline{ab}
\underbrace{ab}
\sqrt[n]{ab}
\frac{a}{b}
x_{k}
\frac{\partial^nf}{\partial x^n}
x =\begin{cases}a & x = 0\\b & x > 0\end{cases}
\big\{a\big\}
\oint_a^b x
\bigsqcup_a^b x
\coprod_a^b x
\bigcup_a^b x
\bigwedge_a^b x
\bigoplus
clear
${}$