f_N(\lambda_n)\left(\frac{0-\left\vert \lambda_n\right\vert^0}{0-\left\vert \Theta(\lambda_n)\right\vert^0}\right)^{\frac{0}{0}}-\frac{a_n}{\left\Vert a\right\Vert_{N,\ell^0}}\right\}\right\Vert_{N,\ell^0}