Equation Icon  Sab(u,θA ) = 2ℰab − Ωa ℰbcΩc − ΩbℰacΩc + δabℰbcΩcΩd + ɛacdΩcℬdb + ɛbcdΩc ℬda, (196 ) A b b c d Sa(u,θ ) = ℰabΩ + ɛabcΩ ℬ dΩ , (197 ) S(u,θA ) = ℰabΩa Ωb. (198 )