Bi′⁡(z)=(z/3)⁢(I2/3⁡(ζ)+I-2/3⁡(ζ))=12⁢(z/3)⁢(ⅇπ⁢ⅈ/3⁢H2/3(1)⁡(ζ⁢ⅇ-π⁢ⅈ/2)+ⅇ-π⁢ⅈ/3⁢H2/3(2)⁡(ζ⁢ⅇπ⁢ⅈ/2))=12⁢(z/3)⁢(ⅇ-π⁢ⅈ/3⁢H-2/3(1)⁡(ζ⁢ⅇ-π⁢ⅈ/2)+ⅇπ⁢ⅈ/3⁢H-2/3(2)⁡(ζ⁢ⅇπ⁢ⅈ/2)),