Defining the right generalized inverse of a non-square Jacobian matrix $J$, $J^{\#}$, as
$J^{\#} = M^{-1} J^T \left(J M^{-1} J^T\right)^{-1}$
where the matrix $M \succ 0$ is positive definite and symmetric, can we infer that the following null space projection matrix
$\left(I - J^\# J \right)$
is non-negative definite?
For the engineering problem that I am tackling, I was able to show that
$M\left( I - J^\# J \right) \succeq 0$