Equation Icon  A c c c d c d c d Sab(u,𝜃 ) = 2ℰab − Ωa ℰbcΩ − ΩbℰacΩ + δabℰbcΩ Ω + 𝜀acdΩ ℬ b + 𝜀bcdΩ ℬ a, (10.59 ) S (u,𝜃A ) = ℰ Ωb + 𝜀 Ωbℬc Ωd, (10.60 ) a A ab a b abc d S(u,𝜃 ) = ℰabΩ Ω . (10.61 )