I⁡(y,k)=exp⁡(ⅈ⁢k⁢A⁡(y))k1/(K+2)⁢∑m=0Kam⁡(y)km/(K+2)⁢(δm,0-(1-δm,0)⁢ⅈ⁢∂∂⁡zm)⁢ΨK⁡(z⁡(y;k))⁢(1+O⁡(1k)),