ref: 59bd46cbf8814ab2a2b26df2a8c0f5481f40f6b4
dir: /sys/src/cmd/python/Doc/tests/math.tex/
\documentclass{howto}
\title{Test of python.sty with math}
\begin{document}
\maketitle
\section{Subscripts in Math Mode}
This contains an inline formula containing a subscript: $H_20$.
This display doesn't make sense, but contains a subscript as well:
$$\sum_1^2 = a_x$$
\end{document}