NULL

testing it out . . .
embedded super and subscript

\(\displaystyle{e^{e^{e^{e^e}}}}\\\displaystyle{a_{1_{2_{3_4}}}}\)

over-/under-line :
\[\begin{array}{|c|c|c|} \hline \overline{A}+\overline{B}=\overline{AB} & \overline{A}\ \overline{B}=\overline{A+B} & A\overline{B}+\overline{A}B=A⊕B\\ \hline {R\\ _{NORMAL}} & {\mathbf{R}\\ _{BOLD}} & {\mathbb{R}\\ _{OUTLINE}}\\ \hline \underline{UNDERLINE} & \overrightarrow{VECTOR} & {A·\cancel{B}\\ _{CANCELING\ ^{1)}\ AN\ OPERAND}} \\ \hline \end{array} \] \[\begin{array}{|c|c|} \hline switch&size\\ \hline \backslash tiny&{\tiny text\ size}\\ \hline \backslash scriptsize&{\scriptsize text\ size}\\ \hline \backslash small&{\small text\ size}\\ \hline \backslash normalsize&{\normalsize text\ size}\\ \hline \backslash large&{\large text\ size}\\ \hline \backslash Large&{\Large text\ size}\\ \hline \backslash LARGE&{\LARGE text\ size}\\ \hline \backslash huge&{\huge text\ size}\\ \hline \backslash Huge&{\Huge text\ size}\\ \hline \end{array} \] \[\begin{array}{|c|c|} \hline switch&color\\ \hline \backslash color\left\{yellow\right\}&{\color{yellow}{colored\ text}}\\ \hline \end{array} \] about ¹⁾ MathJax TeX and LaTeX Support — MathJax 2.7 documentation - TeX and LaTeX extensions