Hi, So it is not easy, perhaps even impossible if the processor doesn't set a flag . e.g. fact n begins first with a lis of negative numbers (after overflow) then comes again a list with positive numbers and then it remains = 0 Scott ----- Original Message ----- From: Xavier Leroy To: Sven LUTHER Cc: Luc Maranget ; Scott J, ; caml-list@inria.fr Sent: Thursday, October 10, 2002 8:57 PM Subject: Re: [Caml-list] Runtime overflow and what to do > But it is the lower bit that is ignored, no, si i guess incrementing an > ocaml integer by 1, correspond to incrementing the machine integer by > two, and would set the overflow flag in the processor status register > all the same, would it not ? Yes, except that not all processors have overflow flags. The Alpha and the MIPS don't, for instance. Integer arithmetic modulo a power of 2 is unpleasant for certain applications (and very useful for others, e.g. hash functions and cryptography), but this is really all what today's processors offer. - Xavier Leroy