Two components of the boundary of \(\text \textbf{I}_3\). (Deux composantes du bord de \(\text \textbf{I}_3\)) Nontriviality of equations and explicit tensors in \(\mathbb{C}^m \otimes \mathbb{C}^m \otimes \mathbb{C}^m\) of border rank at least \(2m - 2\) 