The combinatorics of open covers is a study of Cantor's diagonal argument in various
contexts. The field has its roots in a few basic selection principles that arose from the study of …

Lev Bukovsk$ Ireneusz Reclaw Miroslav Repick$ Page 1 Topology and its Applications 41 (199l)
25-40 North-Holland 25 ea Lev Bukovsk$ Department of Mathematics, University of PJ …

For a Tychonoff space X, we denote by Cp (X) the space of all real-valued continuous
functions on X with the topology of pointwise convergence. We show the following:(1) for the …

The main results of the paper are as follows: covering characterizations of wQN-spaces,
covering characterizations of QN-spaces and a theorem saying that Cp (X) has the …

Showing that every countable set E of reals is a certain type of thin set in the trigonometrical
series theory, NN Bari ([2] p. 737) constructs a sequence of positive reals sk-> 0 and an …

Recently the second author and D. Chandra (2013) began to study the notion of ideal quasi-
normal convergence and some topological notions defined by this convergence. We show …

Nogura showed that whereas Arhangel'skiǐ's properties α1, α2 and α3 are preserved by
finite products, the property α4 is not. It is shown here that for each space X the properties …

In this paper we introduce the notion of exhaustiveness which applies for both families and
nets of functions. This new notion is close to equicontinuity and describes the relation …

In this paper we extend the notion of equal convergence of Császár and Laczkovich with the
help of ideals of the set of positive integers and introduce the ideas of I and I*-equal …

We continue to investigate an ideal version of QN-space, a J QN-space, introduced by P.
Das and D. Chandra [8]. Following R. Filipów and M. Staniszewski [15], we show that an …