Consider the dynamical system in $\mathbb R^n$ where $x_{k+1}=I_nx_k$.
Is the origin a saddle point, a repeller, or an attractor?
All eigenvalues are $1$.
I understand what's going on, the trajectory is a single point, which is the initial vector $x_0$.
But it's not being repelled, attracted, or "saddled."
Would it be none, then?
