At work I am writing a somewhat complex piece of software, and inside it at some point I have to solve the following problem: I have several "streams", each of which has equally spaced points according to a proportionality factor 'a', i.e. X=a*n. Each stream has a different 'a'. As an example: Stream 1, a = 1.5: X = 0, 1.5, 3, 4.5 etc Stream 2, a = 1.0, X = 0, 1, 2, 3 etc Stream 3 .... The question to solve: is there a value X that is a valid point for all streams, other than the trivial 0? This problem strikes me as integer programming, but I have no good idea how to go about it, short of brute force.