Equation Icon  0 a ∂αu = eα[ − Ωaeα, ] (10.29 ) ∂ xˆa = − raa + 1r2Sa + O (r3) e0 α 2 α [ a ( a 1 2 a) 1 2 a 3] b + δ b + ra + 3-r S Ωb + 6r S b + O (r ) eα. (10.30 )