Formula_7003

\[\left.\begin{array}{c}\frac{\partial u_{0}}{\partial t}+\left(v_{0}, \nabla u_{0}\right)=i u_{1} u_{2}, \\\frac{\partial u_{1}}{\partial t}+\left(v_{1}, \nabla u_{1}\right)=i u_{1} u_{2}^{*}, \\\frac{\partial u_{2}}{\partial t}+\left(v_{2}, \nabla u_{2}\right)=i u_{1} u_{1}^{*},\end{array}\right\}\]