contains every two-dimensional normed space
We study weakly precompact sets and operators. We show that an operator is weakly precompact if and only if its adjoint is pseudo weakly compact. We study Banach spaces with the --limited and the -(SR) properties and characterize these classes of Banach spaces in terms of --limited and -Right subsets. The --limited property is studied in some spaces of operators.
The aim of this work is to generalize lacunary statistical convergence to weak lacunary statistical convergence and -convergence to weak -convergence. We start by defining weak lacunary statistically convergent and weak lacunary Cauchy sequence. We find a connection between weak lacunary statistical convergence and weak statistical convergence.