I'm looking for explicit references or algorithms (or, preferably, something along the lines of 'It's obvious, do it like this') for the following problem: I need to compute a basis for the kernel of a linear transformation over Z/mZ, the integers mod m, where m is not prime (specifically 8). It doesn't seem like it should be that hard, but I haven't been able to puzzle out a solid (i.e. codable) procedure for it, and ad hoc methods aren't feasible (some of the matrices I need to solve are 99x50). A program like Maple can do it over a field, but chokes on anything else. Can anyone point me in the right direction?
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