Fuente TeX:

H(X|Y,E) = -\sum_{x \in \mathcal{X} y \in \mathcal{X} e \in \{0,1\}} p(x,y,e) log\left(p(x|y,e)\right) = -\sum_{x \in \mathcal{X} y \in \mathcal{X} e \in \{0,1\}} p(y,e)p(x|y,e) log\left(p(x|y,e)\right) = -\sum_{y \in \mathcal{X} e \in \{0,1\}} p(y,e) H(X|Y=y,E=e)