Typical set
= Typical set
{title2=$T_\varepsilon^{(n)}$}
For an IID source, the epsilon-typical set consists of words $u^n$ satisfying $|-(1/n)\log p(u^n)-H(U)|\leq\varepsilon$. Its probability tends to one, and its cardinality is at most $2^{n(H(U)+\varepsilon)}$.