Proceedings of the American Mathematical Society, Vol. 81, No. 1 (Jan., 1981), pp. 107-110 (4 pages) Let $B$ be a Banach space. It is well known that for every ...

This is a preview. Log in through your library . Abstract Several authors [1], [2], ⋯, [6], have derived characterizations of a conditional expectation operator. That is, if T is a transformation ...