Equation Icon  { } t = u + r 1 − ra (u )Ωa + r2[a (u)Ωa ]2 − 1-r2˙a (u) − 1r2˙a (u)Ωa − 1r2R (u)Ωa Ωb + O (r3)(1,1.1 ) a a 3 0 2 a 3 a0b0