|δn⁡(x)|≤Γ⁡(μ+1)⁢Γ⁡(1-α)Γ⁡(μ+1-α)⁢Γ⁡(n+α)⁢∑j=0n(nj)⁢Γ⁡(n+α-j)|Γ⁡(μ+1-j)|⁢xμ-α