P-12+ⅈ⁢τ-μ⁡(x)=β⁢exp⁡(μ⁢β⁢arctan⁡β)Γ⁡(μ+1)⁢(1+β2)μ/2⁢ⅇ-μ⁢ρ(1+β2-x2⁢β2)1/4⁢(1+O⁡(1μ)),