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Preface

Novák, J. (1977)

General topology and its relations to modern analysis and algebra IV

Preface

Novák, J. (1977)

General topology and its relations to modern analysis and algebra IV

Preface

(1972)

General Topology and its Relations to Modern Analysis and Algebra

Préimages d’espaces héréditairement de Baire

Ahmed Bouziad (1997)

Fundamenta Mathematicae

The main result is slightly more general than the following statement: Let f: X → Y be a quasi-perfect mapping, where X is a regular space and Y a Hausdorff totally non-meagre space; if X or Y is χ-scattered, or if Y is a Lasnev space, then X is totally non-meagre. In particular, the product of a compact space X and a Hausdorff regular totally non-meagre space Y which is χ-scattered or a Lasnev space, is totally non-meagre.

Preimages of Baire spaces

Jozef Doboš, Zbigniew Piotrowski, Ivan L. Reilly (1994)

Mathematica Bohemica

A simple machinery is developed for the preservation of Baire spaces under preimages. Subsequently, some properties of maps which preserve nowhere dense sets are given.

Prescribed ultrametrics

J. Higgins, D. Campbell (1993)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

Preservation and reflection of properties acc and hacc

Maddalena Bonanzinga (1996)

Commentationes Mathematicae Universitatis Carolinae

The aim of the paper is to study the preservation and the reflection of acc and hacc spaces under various kinds of mappings. In particular, we show that acc and hacc are not preserved by perfect mappings and that acc is not reflected by closed (nor perfect) mappings while hacc is reflected by perfect mappings.

Preservation of properties of a map by forcing

Akira Iwasa (2022)

Commentationes Mathematicae Universitatis Carolinae

Let f : X → Y be a continuous map such as an open map, a closed map or a quotient map. We study under what circumstances f remains an open, closed or quotient map in forcing extensions.

Preservation of the Borel class under open-LC functions

Alexey Ostrovsky (2011)

Fundamenta Mathematicae

Let X be a Borel subset of the Cantor set C of additive or multiplicative class α, and f: X → Y be a continuous function onto Y ⊂ C with compact preimages of points. If the image f(U) of every clopen set U is the intersection of an open and a closed set, then Y is a Borel set of the same class α. This result generalizes similar results for open and closed functions.

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