Correction to the paper: On linear functorial operators extending pseudometrics
Correction to the paper: Pairwise monotonically normal spaces
Correction to the paper: Sets invariant under projections onto one dimensional subspaces
Correction to the paper: “Some factorization theorems for paracompact -spaces”
Corrections to my paper "Investigating the ANR-property of metric spaces" (Fund. Math. 124 (1984), 243-254)
Countable Compact Scattered T₂ Spaces and Weak Forms of AC
We show that: (1) It is provable in ZF (i.e., Zermelo-Fraenkel set theory minus the Axiom of Choice AC) that every compact scattered T₂ topological space is zero-dimensional. (2) If every countable union of countable sets of reals is countable, then a countable compact T₂ space is scattered iff it is metrizable. (3) If the real line ℝ can be expressed as a well-ordered union of well-orderable sets, then every countable compact zero-dimensional T₂ space...
Countable dense homogeneity and n-homogeneity
Countable dense homogeneity and λ-sets
We show that all sufficiently nice λ-sets are countable dense homogeneous (𝖢𝖣𝖧). From this fact we conclude that for every uncountable cardinal κ ≤ 𝔟 there is a countable dense homogeneous metric space of size κ. Moreover, the existence of a meager in itself countable dense homogeneous metric space of size κ is equivalent to the existence of a λ-set of size κ. On the other hand, it is consistent with the continuum arbitrarily large that every 𝖢𝖣𝖧 metric space has size either ω₁ or 𝔠. An...
Countable extension of triangular norms and their applications to the fixed point theory in probabilistic metric spaces
Countable products of Čech-scattered supercomplete spaces
We prove by using well-founded trees that a countable product of supercomplete spaces, scattered with respect to Čech-complete subsets, is supercomplete. This result extends results given in [Alstera], [Friedlera], [Frolika], [HohtiPelantb], [Pelanta] and its proof improves that given in [HohtiPelantb].
Countable sums and products of Loeb and selective metric spaces
We investigate the role that weak forms of the axiom of choice play in countable Tychonoff products, as well as countable disjoint unions, of Loeb and selective metric spaces.
Countable-points compactifications for metric spaces
Covering dimension modulo a class of spaces
Covering maps for locally path-connected spaces
We define Peano covering maps and prove basic properties analogous to classical covers. Their domain is always locally path-connected but the range may be an arbitrary topological space. One of characterizations of Peano covering maps is via the uniqueness of homotopy lifting property for all locally path-connected spaces. Regular Peano covering maps over path-connected spaces are shown to be identical with generalized regular covering maps introduced by Fischer and Zastrow....
Covering properties for s with nested bases.
Covering Properties of Continua and Mappings
Covering space theory for directed topology.
Cozero and Baire maps on products of uniform spaces
Criteria of openness for relations
Cyclic Type Fixed Point Results in 2-Menger Spaces
In this paper we introduce generalized cyclic contractions through number of subsets of a probabilistic 2-metric space and establish two fixed point results for such contractions. In our first theorem we use the Hadzic type -norm. In another theorem we use a control function with minimum -norm. Our results generalizes some existing fixed point theorem in 2-Menger spaces. The results are supported with some examples.