A new dimension type
A new extension of countable compactness
A new fixed-point theorem for contractive mappings.
A new form of fuzzy -compactness
A new form of -compactness is introduced in -topological spaces by -open -sets and their inequality where is a complete de Morgan algebra. It doesn’t rely on the structure of the basis lattice . It can also be characterized by means of -closed -sets and their inequality. When is a completely distributive de Morgan algebra, its many characterizations are presented and the relations between it and the other types of compactness are discussed. Countable -compactness and the -Lindelöf property...
A new hyperspace topology and the study of the function space -
A new iterative method for common fixed points of a finite family of nonexpansive mappings.
A new kind of compactness for topological spaces
A new Lindelöf space with points
We prove that implies there is a zero-dimensional Hausdorff Lindelöf space of cardinality which has points . In addition, this space has the property that it need not be Lindelöf after countably closed forcing.
A new look at pointfree metrization theorems
We present a unified treatment of pointfree metrization theorems based on an analysis of special properties of bases. It essentially covers all the facts concerning metrization from Engelking [1] which make pointfree sense. With one exception, where the generalization is shown to be false, all the theorems extend to the general pointfree context.
A new metrization theorem
We give a new metrization theorem on terms of a new structure introduced by the authors in [2] and called fractal structure. As a Corollary we obtain Nagata-Smirnovs and Uryshons metrization Theorems.
A new ordered compactification.
A new semilattice of function algebras and its Boolean form on a lattice of groups.
A new way to find compact zero-dimensional first countable preimages of first countable compact spaces
A nice class extracted from -theory
We study systematically a class of spaces introduced by Sokolov and call them Sokolov spaces. Their importance can be seen from the fact that every Corson compact space is a Sokolov space. We show that every Sokolov space is collectionwise normal, -stable and -monolithic. It is also established that any Sokolov compact space is Fréchet-Urysohn and the space is Lindelöf. We prove that any Sokolov space with a -diagonal has a countable network and obtain some cardinality restrictions on subsets...
A nice subclass of functionally countable spaces
A space is functionally countable if is countable for any continuous function . We will call a space exponentially separable if for any countable family of closed subsets of , there exists a countable set such that whenever and . Every exponentially separable space is functionally countable; we will show that for some nice classes of spaces exponential separability coincides with functional countability. We will also establish that the class of exponentially separable spaces has...
A Nielsen number for fixed points and near points of small multifunctions
A non graph theory approach to Ulam's conjecture
A non-archimedean Dugundji extension theorem
We prove a non-archimedean Dugundji extension theorem for the spaces of continuous bounded functions on an ultranormal space with values in a non-archimedean non-trivially valued complete field . Assuming that is discretely valued and is a closed subspace of we show that there exists an isometric linear extender if is collectionwise normal or is Lindelöf or is separable. We provide also a self contained proof of the known fact that any metrizable compact subspace of an ultraregular...
A non-chainable plane continuum with span zero
A plane continuum is constructed which has span zero but is not chainable.
A non-completely regular quiet quasi-metric.