Ideal QN-spaces (Q892337)

QN-spaces, JQN-spaces, JwQN-spaces and other ideal versions of the QN-spaces were studied extensively and they continue to attract interest, as can be verified by this paper. Among many researchers, P. Das, D. Chandra, Z. Bulovská, L. Bukovský, J. Haleš, I. Reclaw and M. Repický have presented their contributions to the study of the above notions. In this interesting paper, the author continues the study of the QN-spaces. The meaning of the weak \(P(I)\)-ideal is introduced, stating its properties in combination with known ideals such as the \(P\)-ideals and its preservation properties under known orderings between ideals. Moreover, new results on JQN-spaces and on \(S_{1} (\Gamma, \Gamma)\)-spaces complete the investigation.