gradient we start by showing this property that we can write down the gradient of the generator in terms of an expectation where the expectation is we've taken with respect to generator samples and we multiplied f of X by a likelihood gradient that's relatively straightforward to show the basic step is to turn the expectation into an integral use leibnitz's rule which means you have to make a few assumptions about the structure of the distribution involved and then finally we take advantage of our earlier assumption that