equation icon  2(r---M--) ---rD----- G = - r2 + a2 + (r2 + a2)2, (55) [( ) ( )] D2- b,r j,r b,r U1 = V + b 2a + D - j a + D , (56) ,r Kb-- 6D- a = - i D2 + 3iK,r + c + r2 , (57) ( 2D ) b = 2D - iK + r- M - --- . (58) r