If you are modelling vector AB, are there limitations on points A and B? I initially thought that perhaps they'd have to exist within the same set, but surely not right? If point A is purely imaginary and point B purely real for example, the only implication is that your direction vector will have a real and imaginary component right? I'm not sure if I'm misunderstanding something but that is my intuition yet I still feel like there is more to it. Surely there would be no implication if say point B had completely irrational components and point A had completely integer components if both are within the set of real numbers. But say that both are within respectively different sets, B is within the set of all R\Q and A within the set of all Z, surely you can still model vector AB, you would just be navigating each subset.