these distributions here and let's say our X landed over here let's say there's mode 1 mode 2 and we're unlucky and when we sample I from PRI given X we end up with our I equal to somehow well encoding X code X from P of x given I equal 2 is going to be very expensive because there's a low probability here that code is not going to be very efficient at getting X across so it makes it less efficient than what's on the previous slide in fact the difference is that here we have log 1 over P I comma X whereas in the previous