Les Math avec ConTeXt
Math is best delimited inline with \formula{ ... }, not $ ... $
Display math is best delimited with \startformula ... \stopformula ,
not $$ ... $$
\operatorname => \mfunction
The double-, triple-, and quadruple-integrals (\iiiint) are undefined in
basic ConTeXt's math.
The \begin{case} environment needs to be simplified into the Plain
\cases{} command.
The AMSmath/LaTeX-like:
$$ \begin{bmatrix} p & q \\
r & s
\end{bmatrix}
$$
...can be interpreted as...
\startformula
\left[ \matrix{ p & q \cr
r & s
}
\right]
\stopformula