Andrei Alexandrescu: > byte c = a | b; > Say you already know min_a, max_a, min_b, and max_b. How do you compute > min_c and max_c? I thought of it for a bit and it seems quite tricky. This is Interval arithmetic. If you are able to find a book about it... (or a library for some programming language that implements it). Bye, bearophile