MathJax test

$ E=mc^2 $, $m=\sqrt{3+\frac{1}{2}}$

\[ e^{j \pi} + 1 = 0 \]

\[\begin{equation}
\sum_{n=0}^\infty q^n = \frac{1}{1-q}, \quad q \in \mathbb{R}, |q| < 1.
\label{eq:1}\end{equation}\]

cf. eq \ref{eq:2}.

$\mathcal{A,B}, \boldsymbol{\varPsi}$

$\mathbb{A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z}$

\[\begin{equation}f_{X,Y}(x,y) \ = \ \frac{e^{-(x^2+y^2)}}{Z} \label{eq:2} \end{equation}\]

$\sum_{i=0}^n i^2 = \frac{(n^2+n)(2n+1)}{6}$

MathJax 多行公式

$\mathbf{\vec{T}}=\sum\limits_{r=1}^{R}{{{{\mathbf{\vec{H}}}}^{\left( r \right)}}\underset{2}{\mathop{\bullet }}\,}{{\mathbf{A}}^{\left( r \right)}}\underset{3}{\mathop{\bullet }}\,{{\mathbf{B}}^{\left( r \right)}}$

array：
$$ \begin{array}{*{20}{l}}
  {}&{{{{\mathbf{\vec H}}}^{\left( r \right)}} \in {\mathbb{C}^{I \times L \times P}}} \\
  {}&{{{\mathbf{A}}^{\left( r \right)}} \in {\mathbb{C}^{J \times L}}} \\
  {}&{{{\mathbf{B}}^{\left( r \right)}} \in {\mathbb{C}^{J \times L}}}
\end{array}$$

align：
\[\begin{align}
  & {{{\mathbf{\vec{H}}}}^{\left( r \right)}}\in {{\mathbb{C}}^{I\times L\times P}} \\
 & {{\mathbf{A}}^{\left( r \right)}}\in {{\mathbb{C}}^{J\times L}} \\
 & {{\mathbf{B}}^{\left( r \right)}}\in {{\mathbb{C}}^{J\times L}} \\
\end{align}\]

gathered：
\[\begin{gathered}
  {{{\mathbf{\vec H}}}^{\left( r \right)}} \in {\mathbb{C}^{I \times L \times P}} \\
  {{\mathbf{A}}^{\left( r \right)}} \in {\mathbb{C}^{J \times L}} \\
  {{\mathbf{B}}^{\left( r \right)}} \in {\mathbb{C}^{J \times L}} \\
\end{gathered} \]


\[\begin{gathered}
  {{{\mathbf{\vec H}}}^{\left( r \right)}} \in {\mathbb{R}^{I \times L \times P}} \hfill \\
  {{\mathbf{A}}^{\left( r \right)}} \in {\mathbb{Z}^{J \times L}} \hfill \\
  {{\mathbf{B}}^{\left( r \right)}} \in {\mathbb{C}^{J \times L}} \hfill \\
\end{gathered} \]