where each element of the l-dimensional vector c corresponds to an individual constraint expression. The constraints, which may have redundancy, reduce the dimensionality of the optimization problem to 3n -6 -p, where p ≤ l indicates the number of linearly independent constraints. We define the unconstrained and constrained subspaces using the right singular vectors of the l × (3n -6) constraint-nonredundant Jacobian matrix as projection matrices,