Public:Writing LaTeX
Go to Edit of this page to see how it's done (especially see the top of the text where I define new macros the same way as we would do in the regular LaTeX).
Note that there are minor differences with LaTeX. Inline mathematics is typeset with $$...$$, \(...\), and math HTML tag. This means that $...$ won't work! And display style maths is written with \[...\], \begin{XXX}...\end{XXX}, where XXX can be, for example, align.
See for example this $$\Ek A$$ and \(\Pk A\) and also the following:
\[ \Ek A =\ ... \] and \begin{align} \Pk A = ... \end{align}