Characterization of the Oblique Projector $U(VU)^+V$ with Application to   Constrained Least Squares
  We provide a full characterization of the oblique projector $U(VU)^+V$ in the general case where the range of $U$ and the null space of $V$ are not complementary subspaces. We discuss the new result in the context of constrained least squares minimization. 
Ale\v{s} \v{C}ern\'y