Fuente TeX:

H'(\mathcal{X}) = \lim_{n \rightarrow \infty} H(X_n|X_{n-1}...X_1) = \lim_{n \rightarrow \infty} H(X_n|X_{n-1}) = \lim_{n \rightarrow \infty} H(X_2|X_{1}) = -\sum_{i \in \mathcal{X}}\sum_{j \in \mathcal{X}} \pi_i P_{ij} log\left(P_{ij}\right)