F⁡(a,b-λc+λ;-z)=2b-c+(1/2)⁢(z+12⁢z)λ⁢(λa/2⁢U⁡(a-12,-α⁢λ)⁢((1+z)c-a-b⁢z1-c⁢(αz-1)1-a+O⁡(λ-1))+λ(a-1)/2α⁢U⁡(a-32,-α⁢λ)⁢((1+z)c-a-b⁢z1-c⁢(αz-1)1-a-2c-b-(1/2)⁢(αz-1)a+O⁡(λ-1))),