equation icon  X2 = z3{O(1) + eO(z) + e2 [O(1) + O(1) lnz] + ...}, 3 2 X3 = z {O(z) + eO(1) + e [O(z) + O(z) lnz] + ...}, (102) X = z3{ O(zl- 2) + eO(zl -3) + e2 [O(zl -4) + O(zl- 2)ln z]+ ...} for l > 4. l