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. - \sum_{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}