The search session has expired. Please query the service again.

The search session has expired. Please query the service again.

The search session has expired. Please query the service again.

The search session has expired. Please query the service again.

The search session has expired. Please query the service again.

The search session has expired. Please query the service again.

Currently displaying 1 – 3 of 3

Showing per page

Order by Relevance | Title | Year of publication

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.

Finite-to-one continuous s-covering mappings

Alexey Ostrovsky — 2007

Fundamenta Mathematicae

The following theorem is proved. Let f: X → Y be a finite-to-one map such that the restriction f | f - 1 ( S ) is an inductively perfect map for every countable compact set S ⊂ Y. Then Y is a countable union of closed subsets Y i such that every restriction f | f - 1 ( Y i ) is an inductively perfect map.

Page 1

Download Results (CSV)