I've written another big-number library for Lua. This one is based on MAPM,
which contains not only arithmetic but also arbitrary precision transcendental
functions. MAPM is available at http://www.tc.umn.edu/~ringx004/mapm-main.html .
You can get the Lua binding at ftp://ftp.tecgraf.puc-rio.br/pub/lhf/mapm.tar.gz
(I've also updated bclib, my previous big-number library for Lua, so that
both libraries are similar and can share some test code.)
Please send comments, suggestions, and bug reports to [hidden email] .