equal to px given Z and it's also equivalent to P Y given Z comma X being equal to Y given Z this once you know Z X does not tell you anything about Y now to be fair this condition the dependence assumptions that will be making sometimes in the real world might not exactly be true ever but they'll often be reasonable approximations and we might be willing to make him because they drastically simplify the math and the competition we need to do to then run the algorithm in practice so often often these things are assumptions we