On the dimension of increments of Tychonoff spaces
On the metrizability of -spaces and its relationship to the normal Moore space conjecture
On the preservation of separation axioms in products
We give sufficient and necessary conditions to be fulfilled by a filter and an ideal in order that the -quotient space of the -ideal product space preserves -properties () (“in the sense of the Łos theorem”). Tychonoff products, box products and ultraproducts appear as special cases of the general construction.
On the property p and separation axioms for bitopological spaces
On the subsets of non locally compact points of ultracomplete spaces
In 1998, S. Romaguera [13] introduced the notion of cofinally Čech-complete spaces equivalent to spaces which we later called ultracomplete spaces. We define the subset of points of a space at which is not locally compact and call it an nlc set. In 1999, Garc’ıa-Máynez and S. Romaguera [6] proved that every cofinally Čech-complete space has a bounded nlc set. In 2001, D. Buhagiar [1] proved that every ultracomplete GO-space has a compact nlc set. In this paper, ultracomplete spaces which have...
On The Sup And Inf Invariance Of Some Separation Axioms
On the sup and inf invariance of some seperation axioms.
On the weight of nowhere dense subsets in compact spaces.
On -normal and -normal spaces
We define two natural normality type properties, -normality and -normality, and compare these notions to normality. A natural weakening of Jones Lemma immediately leads to generalizations of some important results on normal spaces. We observe that every -normal, pseudocompact space is countably compact, and show that if is a dense subspace of a product of metrizable spaces, then is normal if and only if is -normal. All hereditarily separable spaces are -normal. A space is normal if and...
On -sets and associated weak separation axioms.
On Σ-products of Σ-spaces
Operation-separation axioms in bitopological spaces.
Ordered spaces and quasi-uniformities on spaces of continuous order-preserving functions.
In this paper we introduce and investigate the notions of point open order topology, compact open order topology, the order topology of quasi-uniform pointwise convergence and the order topology of quasi-uniform convergence on compacta. We consider the functorial correspondence between function spaces in the categories of topological spaces, bitopological spaces and ordered topological spaces. We obtain extensions to the topological ordered case of classical topological results on function spaces....
Order-like structure of monotonically normal spaces
For a compact monotonically normal space X we prove: (1) has a dense set of points with a well-ordered neighborhood base (and so is co-absolute with a compact orderable space); (2) each point of has a well-ordered neighborhood -base (answering a question of Arhangel’skii); (3) is hereditarily paracompact iff has countable tightness. In the process we introduce weak-tightness, a notion key to the results above and yielding some cardinal function results on monotonically normal...
Pairwise monotonically normal spaces.
Pairwise monotonically normal spaces
We introduce and study the notion of pairwise monotonically normal space as a bitopological extension of the monotonically normal spaces of Heath, Lutzer and Zenor. In particular, we characterize those spaces by using a mixed condition of insertion and extension of real-valued functions. This result generalizes, at the same time improves, a well-known theorem of Heath, Lutzer and Zenor. We also obtain some solutions to the quasi-metrization problem in terms of the pairwise monotone normality.
Pairwise s-normal spaces
Paracompactness in ordered spaces
Pointless uniformities. I. Complete regularity
Précompactologies et structures uniformes