determinant test

    BLA::Matrix<4,4> denominator = 
    {
                    2,                 1,                  -4,                   0,
                    1,                 0,                   0,                  -1,
                    0,                 1,                   0,                  -3,
                    0,                 0,                   1,                  -1
    };

    BLA::Matrix<4,4> x_numerator = 
    {
                    4,                 1,                  -4,                   0,
                    0,                 0,                   0,                  -1,
                    2,                 1,                   0,                  -3,
                    0,                 0,                   1,                  -1
    };

    BLA::Matrix<4,4> y_numerator = 
    {
                    2,                 4,                  -4,                   0,
                    1,                 0,                   0,                  -1,
                    0,                 2,                   0,                  -3,
                    0,                 0,                   1,                  -1
    };

    BLA::Matrix<4,4> z_numerator = 
    {
                    2,                 1,                   4,                   0,
                    1,                 0,                   0,                  -1,
                    0,                 1,                   2,                  -3,
                    0,                 0,                   0,                  -1
    };

    BLA::Matrix<4,4> t_numerator = 
    {
                    2,                 1,                  -4,                   4,
                    1,                 0,                   0,                   0,
                    0,                 1,                   0,                   2,
                    0,                 0,                   1,                   0
    };

    leg_stance->p.X() = x_numerator.Det() / denominator.Det();
    leg_stance->p.Y() = y_numerator.Det() / denominator.Det();
    leg_stance->p.Z() = z_numerator.Det() / denominator.Det();