stuck exchange

Made an attempt at explaining on X validated why simulating from the joint was equivalent to simulating from the marginal then from the conditional. Unfortunately failed as I could not fathom where the OP’s difficulty was. It seems it started at defining what drawing from a distribution meant… Then someone came by asking why I was writing the exponential in this unusual way (this was a barred E for expectation) and whether or not the “thin hollow rectangle” (a barred I for indicator) was standing for identity, that is

Reaching a point of incomprehension from which I could not recover…