$$
\begin{align}
        B'&=-\nabla \times E,\\
        E'&=\nabla \times B - 4\pi j,
\end{align}
$$

$$
\begin{align}
 A &=     \left(\int_t XXX       \right. \
   &\qquad \left.\vphantom{\int_t} YYY \dots \right)
\end{align}
$$
