Equation Icon  -3δ(δ +-γ +-w)- -3γ(δ +-γ +-w)- ---------w-+-γ-+-δ--------- R ∗ = 2(δ2 − δγ + γ2), S ∗ = 2(δ2 − δγ + γ2), U ∗ = w2 − 3 (γ − δ )2 + 2w (γ + δ), (4.3.9 )