Dear Matt, My name is George and I'm writing from Hungary. I have downloaded your BigIntiger library written in C++. Congratulations, it seems to be very useful and it was a very good job.It works excellent on my box (Lenovo laptop, Ubuntu 8.04 g++ 4.2.4) but are you sure that your code works on any architecture and any compiler? I mean, for example if I'm not mistaken, your arithmetic add function is based on the fact, that GNU C++ compiler handle overflows in additions by decreasing the result. For instance, 0xFFFFFFFF + 0xFFFFFFFF = 0xFFFFFFFE (32-bit architecture, g++) but of course it is not right because the right result is 0x1FFFFFFFE. Of course, you can find out the missing '1' and your code does this so. Do you think that all C++ compilers on all machines handle rollovers caused by these "too big" integer additions? I just ask because it looks like a very good and practical idea and maybe I would also you this method in my codes if it is not a problem, but I have to know if it is reliable or no. I am looking forward to getting your answer. Thank you for reading my e-mail. P.S.: Sorry for my bad english. Yours sincerely, George