Wκ,μ⁡(x)=xX⁢(2⁢μ2-κ⁢x+μ⁢X(μ-κ)⁢x)μ⁢(X+x-2⁢κ2)κ⁢ⅇ-12⁢X-κ⁢(1+O⁡(1μ)),