Wn,3(u,ξ)=|ξ|1/2Jν(u|ξ|1/2)(s=0n-1As(ξ)u2s+O(1u2n-1))-|ξ|Jν+1(u|ξ|1/2)(s=0n-2Bs(ξ)u2s+1+O(1u2n-2)),