Fig. 2

Double-periodic soliton (30) with different parameters of Case (7) \(z=t=1, \ \ y=t=1, \ \ x=t=1, \ \ x=z=1, \ \ x=y=1, \ \ y=z=-2,\ \ x=2,z=-2,\ \ t=2,z=-2,\ \ x=-4,t=1/2\), respectively.
Double-periodic soliton (30) with different parameters of Case (7) \(z=t=1, \ \ y=t=1, \ \ x=t=1, \ \ x=z=1, \ \ x=y=1, \ \ y=z=-2,\ \ x=2,z=-2,\ \ t=2,z=-2,\ \ x=-4,t=1/2\), respectively.