limz→1-⁡(1-z)a+b-c⁢(F⁡(a,b;c;z)-Γ⁡(c)⁢Γ⁡(c-a-b)Γ⁡(c-a)⁢Γ⁡(c-b))=Γ⁡(c)⁢Γ⁡(a+b-c)Γ⁡(a)⁢Γ⁡(b).