On note $\mathcal{A} = \left\{M\in\mathcal{M}_{n}(\mathbb{C}) \hspace{0.2cm} \backslash \hspace{0.2cm} \exists p\in\mathbb{N}^{*} \hspace{0.2cm} : \hspace{0.2cm} M^p = \text{I}_n \right\}$.
Son adhérence est l'ensemble $F = \left\{M\in\mathcal{M}_{n}(\mathbb{C}) \hspace{0.2cm} \backslash \hspace{0.2cm} \text{Sp}(M)\subset\mathscr{C}(0,1) \right\}$