Two components of the boundary of \(\text \textbf{I}_3\). (Deux composantes du bord de \(\text \textbf{I}_3\)) The symmetric function \(h^0(\overline{M}_{0,n},{\mathfrak L}_1^{x_1}\otimes{\mathfrak L}_2^{x_2}\otimes \dots\otimes {\mathfrak L}_n^{x_n})\) 