a1 Department of Mathematical Sciences University of Delaware Newark, Delaware 19716, U.S.A.
a2 Department of Mathematics and Statistics SUNY at Albany 1400 Washington Avenue Albany, New York 12222, U.S.A.
If a function f analytic in Δ = {z
:|z|<1} has a nontangential limit as z→eiθ, then limr→1−(1−r)f′(reiθ)=0 [7, p. 181). It follows that this limit is zero for almost all θ for a number of classes of functions including the set H∞ of bounded analytic functions. In this paper we prove that this result for H∞ is sharp in a strong sense.
(Received March 17 1987)