MathML is a markup language for mathematical notation that can be used with HTML.

If your browser supports it, MathML elements can be used in TiddlyWiki5 WikiText just like HTML.

Here is an example MathML equation from the W3C:

<math><mrow><mo>[</mo><mtable><mtr><mtd><mn>0</mn></mtd><mtd><mn>1</mn></mtd><mtd><mn>0</mn></mtd></mtr><mtr><mtd><mn>0</mn></mtd><mtd><mn>0</mn></mtd><mtd><mn>1</mn></mtd></mtr><mtr><mtd><mn>1</mn></mtd><mtd><mn>0</mn></mtd><mtd><mn>0</mn></mtd></mtr></mtable><mo>]</mo></mrow></math>

Renders as:

$\left[\begin{array}{ccc}0& 1& 0\\ 0& 0& 1\\ 1& 0& 0\end{array}\right]$