**How to write math**

This might be added as a pointer where to find help:

> For some basic information about writing math at this site see e.g. [here](http://meta.stackoverflow.com/questions/68388/there-should-be-universal-latex-mathjax-guide-for-sites-supporting-it/70559#70559), [here](http://meta.math.stackexchange.com/questions/1773/do-we-have-an-equation-editing-howto) and [here](http://math.stackexchange.com/editing-help#latex).

Sometimes this explanation can be useful in the same situation:

> Some MSE users tried to improve your post using TeX (for better readability). Please check whether these edits did not unintentionally change the meaning of your post.