Equation Icon  S (u,𝜃A ) = R + R Ωc + R Ωc + R Ωc Ωd = S , (10.23 ) ab a0b0 a0bc b0ac acbd ba Sa(u,𝜃A ) = SabΩb = Ra0b0Ωb − Rab0cΩbΩc, (10.24 ) S(u,𝜃A ) = S Ωa = R Ωa Ωb, (10.25 ) a a0b0