“…When b(1, 2, 1 * , 2 * ) = 0, that is, b(1, 2) = 0 in (55), resonant interactions can happen. The resonant interactions in this case are called the "minus resonance" [36,37], namely, after the solitons interact with each other, the amplitudes decrease, sometimes the amplitudes can even reach zero. The resonant situation here is similar as the continuous case.…”