The MathJax sandbox

Question

$\require{begingroup} \begingroup \def\safeMathJax{\text{\endgroup error}}$

$$The\ MathJax\ Sandbox$$

It's occasionally difficult to figure out if your MathJax will work in a post, even if it works/doesn't work in the preview. Also, sometimes you want to experiment with stuff that you might use in a puzzle. So... it's always good to have a sandbox. This is primarily for testing $MathJax$, but other formatting tests are also acceptable.

Please try to avoid stuff that will crash people's browsers, okay? Thanks :)

$%invisibletext$

^{MathJax incidentals (copied from @humn)}
_{If you use MathJax-modifying commands such as $\texttt{\def}$ or $\texttt{\let}$ or $\texttt{\newcommand}$ please keep modifications from leaking to other posts by using $\texttt{\begingroup} \raise1.7ex\strut$ and $\texttt{\endgroup}$. The following template is good for this:}

  $\require{begingroup} \begingroup \def\safeMathJax{\text{\endgroup error}}$

  [Answer that includes MathJax code with \def or \let or \newcommand]

  $\endgroup \safeMathJax$

_{If all goes well, the answer will end with (as at the end of this post): $\kern2em\bbox[mistyrose]{\color{red}{\text{\safeMathJax}}} \raise-.8ex\strut$
If $\texttt{\endgroup}$ is not used successfully, the template is meant to show: $~~\text{\endgroup error} \raise-.8ex\strut$
Before posting an answer, be sure to test it on a freshly loaded browser page. Might also need to reload the page while editing, as inadvertent indiscretions in one edit can pervert MathJax results during later edits.}

$\endgroup \safeMathJax$

Answer 1

$%Is it possible to have an entirely blank post?$

Answer 2

$\require{begingroup} \begingroup \def\safeMathJax{\text{\endgroup error}}$

This is an answer.

$\endgroup \safeMathJax$

Answer 3

Testing special characters

Unicode: ߥ DDagger

HTML: ‡

MathJax $\ddagger$

Answer 4

This is a test post for hovering text in comments. Ignore me.