数学符号表

\forall
\exists
\in
\subseteq
\Rightarrow
\Longleftrightarrow
\leq
\trianglelefteq
\ker
\operatorname{Im}
\langle a \rangle
\square

$
\exists
\in
\subseteq
\Rightarrow
\Longleftrightarrow



\operatorname{Im}

\square
$