By writing i as a polynomial in z i = airz r + airsz rz s/2! +

By writing ξi as a polynomial in z

ξi = airz r + airsz rz s/2! + airstz rz sz t/3! + …, solve the equation

κ

r,iξi + κ

r,i,jξiξj/2! + κ

r,i,j,kξiξjξk/3! + ⋯ = z r

by series reversal. Hence derive expansion (6.12) for K*(x).