kaTex
https://katex.org/docs/supported.html
\frac{A}{B} \ {A \over B } \ \quad \
\quad\quad \cfrac{A}{B}
\frac{A}{B} \ {A \over B } \ \quad \
\quad\quad \cfrac{A}{B} A_B \ne A^B \\
\rightarrow \bar{A} \lambda \
A_B \ne A^B \\
\rightarrow \bar{A} \lambda \ \color{blue}{what}
\color{blue}{what} 
