By considering the order of magnitude of the occupation numbers \(\left\langle n_{\varepsilon}ightangle\), show that it makes no difference to the final results of Section 7.1 if we combine a finite number of \((\varepsilon eq 0)\)-terms of the sum (7.1.2) with the \((\varepsilon=0)\)-part of equation (7.1.6) or include them in the integral over \(\varepsilon\).