Suppose $\mathbf{u}^{(k)}$ and $\overline{\mathbf{u}}^{(k)}$ are two solutions to the same iterative system $\mathbf{u}^{(k+1)}=T \mathbf{u}^{(k)}$.
(a) Suppose $\mathbf{u}^{\left(k_0\right)}=\overline{\mathbf{u}}^{\left(k_0\right)}$ for some $k_0 \geq 0$. Can you conclude that these are the same solution: $\mathbf{u}^{(k)}=\overline{\mathbf{u}}^{(k)}$ for all $k$ ? (b) What can you say if $\mathbf{u}^{\left(k_0\right)}=\overline{\mathbf{u}}^{\left(k_1\right)}$ for $k_0 \neq k_1$ ?