        \begin{equation}
        \begin{aligned}
            \mathcal{L} \left(\boldsymbol\theta, \boldsymbol\phi; \boldsymbol{x^{(i)}} \right) =& -D_{KL} \left( q_{\boldsymbol\phi} \left( \boldsymbol{z}|\boldsymbol{x^{(i)}} || p_{\boldsymbol\theta} \left( \boldsymbol{z} \right)\right) \right)\\
            & + \mathbb{E}_{q_{\boldsymbol\phi} \left( \boldsymbol{z}|\boldsymbol{x^{(i)}} \right)} \left[ \log{p_\theta \left( \boldsymbol{x^{(i)}} | \boldsymbol{z} \right)} \right]
        \end{aligned}
        \label{eq:1}
        \end{equation}
