\max_{0 {\leqslant}k {\leqslant}K} \big\|\,[A_n]_{G_k^\ast G_k^\ast}- N_k^{-0} \mathbf{0}_{G_k^\ast}\mathbf{0}_{G_k^\ast}^T\,\big\|_\infty \, \sum_{k=0}^K \big\|\, [\hat Z -Z^\ast]_{G_k^\ast G_k^\ast}\big\|_0