This library is copied from https://web.tecgraf.puc-rio.br/~lhf/ftp/lua/ar/lbc-101.tar.gz

The original text of README in the source is as below.


This is an arbitrary precision library for Lua. It is based on the
number.c library written by Philip A. Nelson for GNU bc:
	http://www.gnu.org/software/bc/

To build the library and run a simple test, just do make.
If Lua is not installed in /usr/local, tell make:
	make LUA_TOPDIR=/var/tmp/lhf/lua-5.3.5/install

To install the library where Lua can find it, use a variant of these:
	make install
	sudo make install
	sudo make install LIBDIR=/usr/local/lib/lua/5.3

For detailed installation instructions, see
	http://www.tecgraf.puc-rio.br/~lhf/ftp/lua/install.html

The library is simple and intuitive; see the summary below.
Read test.lua to see the library in action.

This code is hereby placed in the public domain and also under the MIT license.
The bc code in src/ has its own license. See src/COPYING.

Please send comments, suggestions, and bug reports to lhf@tecgraf.puc-rio.br .

bc library:
__add(x,y)	__pow(x,y)	digits([n])	new(x)		tostring(x)
__div(x,y)	__sub(x,y)	div(x,y)	pow(x,y)	trunc(x,[n])
__eq(x,y)	__tostring(x)	isneg(x)	powmod(x,y,m)	version
__le(x,y)	__unm(x)	iszero(x)	quotrem(x,y)
__lt(x,y)	abs(x)		mod(x,y)	sqrt(x)
__mod(x,y)	add(x,y)	mul(x,y)	sub(x,y)
__mul(x,y)	compare(x,y)	neg(x)		tonumber(x)