# Chapter 22 The num library: arbitrary-precision rational arithmetic

The `num` library implements integer arithmetic and rational arithmetic in arbitrary precision.
More documentation on the functions provided in this library can be found in The CAML Numbers Reference Manual by Valérie Ménissier-Morain, technical report 141, INRIA, july 1992 (available electronically, `ftp://ftp.inria.fr/INRIA/publication/RT/RT-0141.ps.gz`).
Programs that use the `num` library must be linked as follows:

            ocamlc other options nums.cma other files
            ocamlopt other options nums.cmxa other files

For interactive use of the `nums` library, do:

            ocamlmktop -o mytop nums.cma
            ./mytop

or (if dynamic linking of C libraries is supported on your platform), start `ocaml` and type `#load "nums.cma";;`.

- Module `Num`: operation on arbitrary-precision numbers
- Module `Big_int`: operations on arbitrary-precision integers
- Module `Arith_status`: flags that control rational arithmetic