“…In this paragraph, we make some remarks on the existing work that is closely related to our present work. Indeed, in the past one or two decades, many efforts have been made to rigorously justify various equations, such as the nonlinear Schrödinger equation, 15,18,22 the KdV equation, 2,5,8,21,25,32 the KP equation, 5,13,14,19,24,31,33,36,37 the Zakharov-Kuznetsov (ZK) equation, 20,31 and the Ostrovsky equation. 28 Whether the KP equation provides a good approximation to the 2D RQEP system is not known.…”