Karamzadeh, O. A. S.; Namdari, M.; Soltanpour, S.(Universitat Politècnica de València, 2015-10-01)
[EN] Let $C_c(X)=\{f\in C(X) : |f(X)|\leq \aleph_0\}$, $C^F(X)=\{f\in C(X): |f(X)|<\infty\}$, and $L_c(X)=\{f\in C(X) : \overline{C_f}=X\}$, where $C_f$ is the union of all open subsets $U\subseteq X$ such that ...
Protasov, Igor V.(Universitat Politècnica de València, 2021-10-01)
[EN] Given a coarse space (X, E), we endow X with the discrete topology and denote X ♯ = {p ∈ βG : each member P ∈ p is unbounded }. For p, q ∈ X ♯ , p||q means that there exists an entourage E ∈ E such that E[P] ∈ q for ...
Alas, Ofelia T.; Madriz-Mendoza, Maira; Wilson, Richard G.(Universitat Politècnica de València, 2012-04-01)
[EN] We prove some cardinal inequalities valid in the classes of Whyburn and hereditarily weakly Whyburn spaces and we construct examples of non-Whyburn and non-weakly Whyburn spaces to illustrate that some previously known ...