ABSTRACT
These functions are analytic in D, their only singularity being a branch point at z = z,. Theorem 11.1 of Chapter 6 informs us that if z, is excluded from D, then equation (1 1.01) has a solution which depends on an arbitrarily chosen point a of D, and is given by
I&(z)I G exp{"Y,,,(F)) - 1 (z H(a)). (1 1.04) Here H(a) comprises the points z that can be linked to a by a t-progressive path lying in D, and the variation in (1 1.04) is evaluated along such a path. Depending on the choice ofa and the branches of t(z) and f -'I4(z), we obtain differing solutions of the differential equation.
