without latex delimiters the _{i=1} in \sum_{i=1}^n a_n is interpreted as subscript.
we support \(...\), \[...\], $$...$$ and \begin{$env}...\end{$env} as latex fragment delimiters.
∑i=1^n a_n (without latex delimiter)
\(\sum_{i=1}^n a_n\)
\[\sum_{i=1}^n a_n\]
$$\sum_{i=1}^n a_n$$
\begin{xyz}\sum_{i=1}^n a_n\end{xyz}
\begin{xyz} \sum_{i=1}^n a_n \end{xyz}
$2 + 2$, $3 - 3$