People, When intending to write a library for large numbers, it worths to keep in mind the following. 1. Efficient multiplication, division and gcd methods may occur rather involved mathematically. 2. It is natural for `arithmetics' to include factorization. Suppose, GHC would like to include such ... 3. It is natural to extend further the library to algebraic numbers. (2) and (3) are definitely very involved mathematically. (2) and (3) are supported by existing libraries (by Lenstra or other experts), -- as I recall, written in C, -- with various wise methods for (1),(2),(3), so that efficient arithmetics for integers is extended to algebraic numbers. (I never looked into all this, only have seen the announcements). Regards, ----------------- Serge Mechveliani mechvel@botik.ru