Polynomial set-valued functions
The aim of this paper is to give a necessary and sufficient condition for a set-valued function to be a polynomial s.v. function of order at most 2.
Pontryagin duality for convergence groups of unimodular continuous functions
Positive definite functions and coincidences
Préimages d’espaces héréditairement de Baire
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
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
Preservation of properties of a map by forcing
Let be a continuous map such as an open map, a closed map or a quotient map. We study under what circumstances remains an open, closed or quotient map in forcing extensions.
Preservation of the Borel class under open-LC functions
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.
Presheaves over the sets which need not be well ordered, functional separation of their inductive limits and their representation by sections
Prime mappings, number of factors and binary operations [Book]
Primitive words and spectral spaces.
Products and sums of absolute proper retracts
Products and sums of absolute proper retracts, II
Products as reflections
Products of Baire topological vector spaces
Products of simply continuous and quasicontinuous functions
Produit topologique, produit tensoriel et -replétion
Projectively generated convergence of sequences
Projectively Solid Sets and an N-dimensional Piccard's Theorem
We discuss functions f : X × Y → Z such that sets of the form f (A × B) have non-empty interiors provided that A and B are non-empty sets of second category and have the Baire property.
Projectivity of pure ideals