Bi⁡z=z/3⁢I1/3⁡ζ+I-1/3⁡ζ=12⁢z/3⁢ⅇπ⁢ⅈ/6⁢H1/31⁡ζ⁢ⅇ-π⁢ⅈ/2+ⅇ-π⁢ⅈ/6⁢H1/32⁡ζ⁢ⅇπ⁢ⅈ/2=12⁢z/3⁢ⅇ-π⁢ⅈ/6⁢H-1/31⁡ζ⁢ⅇ-π⁢ⅈ/2+ⅇπ⁢ⅈ/6⁢H-1/32⁡ζ⁢ⅇπ⁢ⅈ/2,