w4⁢(z)=ⅇ(b-c)⁢π⁢ⅈ⁢Γ⁡(c-a-b+1)⁢Γ⁡(b-a)Γ⁡(1-a)⁢Γ⁡(c-a)⁢w5⁢(z)+ⅇ(a-c)⁢π⁢ⅈ⁢Γ⁡(c-a-b+1)⁢Γ⁡(a-b)Γ⁡(1-b)⁢Γ⁡(c-b)⁢w6⁢(z).