my Latex and Tex4ht cheat sheet

2.43 Some lualatex examples using Lua inside Latex
2.43.1 Making counter
% !TEX TS-program = lualatex
\documentclass{article}
\usepackage{luacode}
\usepackage{amsmath}
%------------------------
\begin{luacode}
local x = 0
function add()
x = x +1
tex.print(x)
end
function sub()
x = x - 1
tex.print(x)
end
function reset()
x = 0
end
\end{luacode}
\newcommand\add[0]{ \directlua{add()}}%
\newcommand\sub[0]{ \directlua{sub()}}%
\newcommand\reset[0]{ \directlua{reset()}}%
%-------------------
\begin{document}
\reset
\add
\add
\sub
\add
\end{document}
2.43.2 simplify fraction
see http://tex.stackexchange.com/questions/253693/reducing-fraction-using-latex-3/253716#253716
41