1. J. K. Storrow:Nuovo Cimento,54 A, 15 (1968), henceforth referred to as I.
2. R. J. Glauber:Phys. Rev.,131, 2766 (1963).
3. It was shown in Sect.4 of I that the operatorD[f p ] creates a «cloud» of soft photons. We could project out eigenstates of energy momentum as shown there. It makes no difference to the final result.
4. V. Chung:Phys. Rev.,140, B 1110 (1965).
5. D. R. Yennie andH. Suura:Phys. Rev.,105, 137 (1967).