Integral solutions of rational linear equations

[Thomas Gazagnaire <thomas.gazagnaire@irisa.fr>]

Hello,

in my one of my Ocaml programs, I need to find all integers solutions of 
a rational equation systems. This algo uses Gauss reduction and Hermite 
normal form, and need to know if a rational is an integer or not (ie. I 
don't want to use numerical approximation : (1/3) * 3 is an integer but 
0,333333*3 we don't know). I didn't find any integer algebra package for 
ocaml, so I tried to implement Gauss elimination (easy) and Hermite 
normal form (more difficult...). But I didn't implement optimized 
version of these algorithms...

So my question is : do you know if exists a native ocaml module or an 
interface with a C library which is able to do integer/rational matrix 
manipulation (essentialy the Hermite normal form) in an efficient way ?

Thomas