“…-As x -> oo, (1.9) ©,,(a) = S ,7^--^ + 0(^ log ^)- If y is quite close to x, the error term in (1.11) is not very good, and at first sight one might hope to do better. However, on inspecting F(oc, ^) one finds that the error can indeed be this large, and is essentially due to the irregular behaviour of F(a, ^) as a function of S at the points 2,3, ... (see Lemma 4 of [9]). …”