Abstract
In the paper [1] we have to change the definition of the class introduced at pag. 209. The new definition is now the following:
is the subset of
whose elements f satisfy the following assumption:
for every λ > 0.
If the same holds for bf for any constant λ > 0, and moreover Theorem 3, page 209, is now valid for any λ > 0. Theorem 4 still holds in the same form, and the slight modifications to the proofs of theorems 3 and 4 are now obvious. No other essential changements are required in the applications.