Schur's Lemma for Coupled Reducibility and Coupled Normality

Dana Lahat, Christian Jutten, Helene Shapiro

Let $\mathcal{A}=\{A_{ij}{\}}_{i,j\in \mathcal{I}}$, where $\mathcal{I}$ is an index set, be a doubly indexed family of matrices, where $A_{ij}$ is $n_i\times n_j$. For each $i \i…