Free topological groups over metrizable spaces

Proto-metrizable fuzzy topological spaces

Basic Properties of Metrizable Topological Spaces

We continue Mizar formalization of general topology according to the book [16] by Engelking. In the article, we present the final theorem of Section 4.1. Namely, the paper includes the formalization of theorems on the correspondence between the cardinalities of the basis and of some open subcover, and a discreet (closed) subspaces, and the weight of that metrizable topological space. We also de...

Lindelöf spaces C ( X ) over topological groups

Theorem 1 proves (among the others) that for a locally compact topological group X the following assertions are equivalent: (i) X is metrizable and s-compact. (ii) CpðXÞ is analytic. (iii) CpðXÞ is K-analytic. (iv) CpðXÞ is Lindelöf. (v) CcðX Þ is a separable metrizable and complete locally convex space. (vi) CcðX Þ is compactly dominated by irrationals. This result supplements earlier results ...

Fréchet-urysohn Spaces in Free Topological Groups

Let F (X) and A(X) be respectively the free topological group and the free Abelian topological group on a Tychonoff space X. For every natural number n we denote by Fn(X) (An(X)) the subset of F (X) (A(X)) consisting of all words of reduced length ≤ n. It is well known that if a space X is not discrete, then neither F (X) nor A(X) is Fréchet-Urysohn, and hence first countable. On the other hand...

Free topological groups of weak P - spaces

It is known that the free topological group over the Tychonoff space X, denoted F(X), is a P space if and only if X is a P -space. This article is concerned with the question of whether one can characterize when F(X) is a weak P -space, that is, a space where all countable subsets are closed. Our main result is that F(X) is a weak P -space if and only if X is a weak P -space and every countable...