This paper considers direct sums of normed spaces with respect to a Banach space with a normalised, unconditionally strictly monotone basis. Necessary and sufficient conditions are given for such direct sums to have the λ-property. These results are used to construct examples of reflexive Banach spaces U and V such that U has the uniform λ-property but U* fails to have the λ-property, while V and V* fail to have the λ-property.

A Skorokhod embedding approach is used to give the other law of the iterated logarithm for square integrable martingales.

Let n be a positive integer, Bn the closed unit ball in Euclidean n-space, and X any countable CW-complex of dimension at most n. It is shown that the free Abelian topological group on Bn, F(Bn), has F(X) as a closed subgroup. It is also shown that for every differentiable manifold Y of dimension at most n, F(Y) is a closed subgroup of F(Bn).

A new minimax inequality on H-spaces is obtained together with six equivalent formulations. As applications, some results on fixed point theorems and system of inequalities are proved. Our results generalise the corresponding results on (1) minimax inequalities due to Fan, Yen, Tan, Shih-Tan and Ding-Tan, (2) fixed point theorems due to Browder, Tarafdar, Shih-Tan and Ding-Tan, (3) convex inequalities due to Fan, (4) systems of inequalities due to Granas-Liu and (5) a minimax theorem due to Kneser.

For each t ∈ {0,1,2,…}, let Tt be a set of operators in a Banach space. Tt is called a multiple semigroup of operators with respect to some operation ⊗ between sets of operators, if Tt satisfies the semigroup property Tt+s = Tt⊗Ts. Two operations, (∘) and (·), between sets of operators are defined and properties of Tt are studied. Applications to the theory of Controlled Markov Processes are considered.

By applying a minimax inequality on H-spaces from our earlier work, new generalisations of well-known intersection theorems concerning sets with convex sections and minimax inequalities of von Neumann type are obtained. Our results generalise the corresponding results of Ben-El-Mechaiekh, Deguire and Granas, Fan, Liu, Shih-Tan, Sion and Tarafdar.

In this paper we study internal completeness, injectivity and some related notions in the category MBoo of Boolean algebras in the topos MEns of M-sets, for a monoid M.

By using the method of differential subordinations, we derive, among other results, some criteria for univalency in the unit disc.

A useful result for uniformly bounded sequences of functions in Orlicz spaces is generalised by means of a recent extension of Komlós' theorem. The same generalisation can also be proven differently, by means of Young measures.

Rolewicz' drop property is a modification of a concept underlying Daneš' drop theorem. We characterise the drop property by the upper semicontinuity and compact valued property of the duality mapping for the dual. The characterisation suggests that we define a weak drop property which we show characterises the reflexivity of the space.

Let X = {xk}k≥1 be a sequence of positive integers. Let Qk = [O;xk,xk−1,…,x1] be the finite continued fraction with partial quotients xi(1 ≤ i ≤ k). Denote the set of the limit points of the sequence {Qk}k≥1 by Λ(X). In this note a necessary and sufficient condition is given for Λ(X) to contain no rational numbers other than zero.