Esν2⁢m+2⁡(z1,k2)⁢ⅆ⁡w2⁡(z)/ⅆ⁡z|z=K-ⅆ⁡w2⁡(z)/ⅆ⁡z|z=-Kw2⁡(0)=-k4k′⁢sn⁡(z1,k)⁢cn⁡(z1,k)⁢∫-KKsn⁡(z,k)⁢cn⁡(z,k)⁢ⅆ2⁡Pν⁡(y)ⅆ⁡y2⁢Esν2⁢m+2⁡(z,k2)⁢ⅆ⁡z.