Equation Icon  [ a 1- 2 3 ] ˙p(u) = − 1 + raaΩ + 3 r S + O (r ) , ( a) 2 ¨p(u) = − r ˙a0 + ˙aaΩ + O (r ), p(3)(u) = ˙a0 + O (r ),