更改

<math>

<math>

\begin{aligned}

\begin{aligned}

EI&=\frac{1}{\#(\mathcal{X})} (-\sum_{x\in\mathcal{X}}H(Pr(Y|X)) + H(Pr(Y))\\

EI&=\frac{1}{\#(\mathcal{X})} \left(-\sum_{x\in\mathcal{X}}H(Pr(Y|X))\right) + H\left(Pr(Y)\right)\\

\end{aligned}

\end{aligned}

</math>

</math>