Let (Rn(x))n∈N0 be an orthogonal sequence inducing a polynomial hypergroup on N0. The basic facts on polynomial hypergroups and their characters can be found in the monograph [1] or in the papers [6, 7]. A recent review is [8]. The Banach space of almost periodic functions on hypergroups is introduced and studied by the author in [5]. Weakly almost periodic functions are the topic of [12]. It i...

We introduce a new class of functions called θ-precontinuous functions which is contained in the class of weakly precontinuous (or almost weakly continuous) functions and contains the class of almost precontinuous functions. It is shown that the θprecontinuous image of a p-closed space is quasi H-closed. 2000 Mathematics Subject Classification. 54C08.

Abstract In this note, we deduce a strengthening of the Orlicz–Pettis theorem from Itô–Nisio theorem. The argument shows that given any series in Banach space which is not summable (or more generally unconditionally summable), can construct (coarse-grained) subseries with property that—under some appropriate notion “almost all”—almost all further thereof fail to be weakly summable. Moreover, by...