Yes Xn is a sequence. Your other post uses the same variable, so let us say that the converging sequence is Yn instead of Xn; then if you have a set of random variables X1...Xn, Yn = -1/n*log(p(X1...Xn)), and this Yn converges in probability to H(X) (as N->infinity, Pr(|Yn-H(X)|>epsilon)->0).
Yes Xn is a sequence. Your other post uses the same variable, so let us say that the converging sequence is Yn instead of Xn; then if you have a set of random variables X1...Xn, Yn = -1/n*log(p(X1...Xn)), and this Yn converges in probability to H(X) (as N->infinity, Pr(|Yn-H(X)|>epsilon)->0).
X^n and Xn are just notation. Different people and different books use different notation; you have to pay attention to the context to see which one is being used.
X^n and Xn are just notation. Different people and different books use different notation; you have to pay attention to the context to see which one is being used.