ref: 2eed8c40d156ddd48da8019e2a1bd3a5d6d11ee6
dir: /sys/src/cmd/python/Doc/texinputs/python.ist/
line_max 100
headings_flag 1
heading_prefix " \\bigletter "
preamble "\\begin{theindex}
\\def\\bigletter#1{{\\Large\\sffamily#1}\\nopagebreak\\vspace{1mm}}
"
symhead_positive "{Symbols}"
numhead_positive "{Numbers}"