Bi′⁡-z=z/3⁢J-2/3⁡ζ+J2/3⁡ζ=12⁢z/3⁢ⅇπ⁢ⅈ/3⁢H2/31⁡ζ+ⅇ-π⁢ⅈ/3⁢H2/32⁡ζ=12⁢z/3⁢ⅇ-π⁢ⅈ/3⁢H-2/31⁡ζ+ⅇπ⁢ⅈ/3⁢H-2/32⁡ζ.