\begin{matrix} x & y \\ z & w \end{matrix}
\begin{array}{cc} x & y \\ z & w \end{array}
\begin{pmatrix} x & y \\ z & w \end{pmatrix}
\begin{bmatrix} x & y \\ z & w \end{bmatrix}
\begin{vmatrix} x & y \\ z & w \end{vmatrix}
\begin{Vmatrix} x & y \\ z & w \end{Vmatrix}
\begin{Bmatrix} x & y \\ z & w \end{Bmatrix}
\begin{array}{c:c:c} x & y \\ z & w \end{array}
\begin{array}{c|c} x & y \\ \hdashline z & w \end{array}
\begin{rcases} x \\ y \end{rcases}
\begin{rcases} x \\ y \end{rcases} \Rightarrow z
\begin{smallmatrix} x & y \\ z & w \end{smallmatrix}
\begin{subarray}{l} i < n \\ j < m \end{subarray}
\begin{equation} x + y = z \end{equation}
\begin{split} x &= y + z \\ &= w \end{split}
\begin{align} x &= y \\ z &= w \end{align}
\begin{gather} x = y \\ z = w \end{gather}
\begin{alignat}{2} x &= y &&+ z \\ w &= u &&+ v \end{alignat}
\begin{CD} A @>>> B \\ @VVV @VVV \\ C @>>> D \end{CD}
\begin{matrix*}[r] -x & y \\ z & -w \end{matrix*}
\begin{array}{cc} x & y \\ \hline z & w \end{array}
\begin{array}{c} A \\ \begin{array}{cc} x & y \end{array} \end{array}
\href{https://katex.org/}{\KaTeX}
\includegraphics[height=0.8em, totalheight=0.9em, width=0.9em, alt=KA logo]{https://katex.org/img/khan-academy.png}
\htmlStyle{color: red;}{x}
\htmlData{foo=a, bar=b}{x}
\includegraphics[height=1em]{https://katex.org/img/khan-academy.png}
\overbrace{a+b+c}^{\text{note}}
\underbrace{a+b+c}_{\text{note}}
\overbracket{a+b+c}^{\text{note}}
\underbracket{a+b+c}_{\text{note}}
\sum_{\substack{0<i<m\\0<j<n}}
\left(x^{\smash{2}}\right)
\sum\limits_{\mathclap{1\le i\le j\le n}} x_{ij}
\text{a}\kern{1em}\text{b}
\text{a}\mkern{18mu}\text{b}
\text{a}\mskip{18mu}\text{b}
\text{a}\hskip{1em}\text{b}
\text{a}\hspace{1em}\text{b}
\text{a}\hspace*{1em}\text{b}
\text{a}\kern 1em \text{b}
\text{a}\mkern 18mu \text{b}
\text{a}\mskip 18mu \text{b}
\text{a}\hspace{1em}\text{b}
\def\foo{x^2} \foo + \foo
\gdef\foo#1{#1^2} \foo{y} + \foo{y}
\global\def\macroname#1#2…{definition}
\newcommand\macroname[numargs]{definition}
\renewcommand{\macroname}[1]{definition}
\providecommand{\macroname}[1]{definition}
\text{line 1}\newline\text{line 2}
\long\def\macro{definition}
\TextOrMath{\text{text}}{\text{math}}
\@ifstar{\text{star}}{\text{no star}}
\@ifnextchar{x}{\text{yes}}{\text{no}}
\genfrac ( ] {2pt}{1}a{a+1}
\cfrac{a}{1 + \cfrac{1}{b}}
\operatornamewithlimits{f}
\xrightarrow[under]{over}
\Braket{ ϕ | \frac{∂^2}{∂ t^2} | ψ }
\textcolor{#228B22}{F=ma}
\fcolorbox{red}{aqua}{$F=ma$}
\displaystyle\sum_{i=1}^n
\text{\textquotedblright}