Infra-red divergence enforces a rearranged perturbation expansion

In an earlier paper it has been shown for the case of scalar electrodynamics that the ordinary perturbation expansion (OPE) must, except in certain cases, be rearranged in order to uniquely carry out the infra-red (IR) exponentiation in a translation and gauge-invariant way. The uniqueness of the exponent of order α follows from requiring exact order-by-order agreement with the OPE before summation and also from requiring that exponentiation of all factorizable parts must be done before integration. This technique is here applied to ordinary spinor QED and a similar result is obtained without making the γ-matrix algebra more complicated than in the OPE. This technique explicity exhibits the structure of the remaining IR-regular part, which appears in terms of a correlation expansion with respect to photon momenta