Whipple [6] was the first to consider transformations connecting well-poised hypergeometric series as particular cases of relations between cognate trigonometrical series. He used contour integrals of the Barnes type to deduce such transformations. Later Sears [3] gave a systematic theory of general and well-poised transformations of trigonometrical series of any order which included Whipple's results as particular cases.

A distribution function ø(x) is assumed to have the following properties

(1) ø(x) is non-decreasing

If f(x) is denned on [0, 1], then its corresponding Bernstein polynomial

approaches f(x) uniformly on [0, 1], if f(x) is continuous on [0, 1]. If f(x) is bounded on [0, 1], then at every point x where the second derivative exists (Voronowskaja [7], see also [5])

Kothe spaces, in the terminology of Diendonné [2], are certain spaces X of real valued integrable functions. In this paper we consider the problem of representation of continuous linear functional on vector valued Kothe spaces. The elements of a Kôthe space X(B) are functions with values in a Banach space B (see §2).

In this paper we introduce the function spaces Lx and Lx(5) which generalize the classical Lp and Lp(B) spaces respectively. For those λ which possess what we call the levelling property we give a discussion of the conjugate space to Lλ(B); our treatment applies, in particular, to the L(W)p(B) and M(W)q(B) spaces defined in [7, §2]. (See also the note at end of this paper.)