Thank you guys for all your help. It's kinda late now, so I will look it up tomorrow or this weekend. If I happen to have any more doubts/problems, I will let you know =p

Thanks for your answer, I will try to port my code to do it your way.

But doing it that way will I be able to do something like this:

V:= < a, b>;

> simplify(M . V) mod 2;

Where 'a' and 'b' are unassigned variables ?

Thanks once again.