if you want to so that makes it very convenient and also that it's never going to be better than the entropy and expected encoding length for she might have next n as well how close can we get to entropy can we find the code that achieves that achieves H of X or it close to it because if we can and we know we're doing optimal okay so here's one way to think of it expected code length would be entropy if we take the lengths of all of them exactly this thing over here on the inside the coding is log to 1 over P of