J.H. Caltenco, José Luis Lopez-Bonilla, B.E. Carvajal-Gámez, P. Lam-Estrada, Singular Value Decomposition, BSMaSS Volume 11, The Bulletin of Society for Mathematical Services and Standards (Volume 11)
    We study the SVD of an arbitrary matrix A<sub>nxm</sub>, especially its subspaces of activation, which leads in natural manner to pseudoinverse of Moore-Bjenhammar-Penrose. Besides, we analyze the compatibility of linear systems and the uniqueness of the corresponding solution, and our approach gives the Lanczos classification for these systems.
    Compatibility of Linear Systems, Pseudoinverse of a Matrix, SVD