Equation Icon  [ a 1 2 3 ] 0 [( b 1 2 ) 1 2 3 ] a ∂αr = − raa Ω + --rS + O (r ) eα + 1 + rabΩ + -r S Ωa + -r Sa + O (r ) eα, (10.31 ) 2 3 6