Czasopismo
Tytuł artykułu
Autorzy
Warianty tytułu
Języki publikacji
Abstrakty
We first prove that given any analytic filter ℱ on ω the set of all functions f on $2^{ω}$ which can be represented as the pointwise limit relative to ℱ of some sequence $(fₙ)_{n∈ω}$ of continuous functions ($f = lim_{ℱ} fₙ$), is exactly the set of all Borel functions of class ξ for some countable ordinal ξ that we call the rank of ℱ. We discuss several structural properties of this rank. For example, we prove that any free Π⁰₄ filter is of rank 1.
Słowa kluczowe
Kategorie tematyczne
- 54H05: Descriptive set theory (topological aspects of Borel, analytic, projective, etc. sets)
- 54A20: Convergence in general topology (sequences, filters, limits, convergence spaces, etc.)
- 03E15: Descriptive set theory
- 03E45: Inner models, including constructibility, ordinal definability, and core models
Czasopismo
Rocznik
Tom
Numer
Strony
189-213
Opis fizyczny
Daty
wydano
2009
Twórcy
autor
- Analyse Fonctionnelle, Institut de Mathématique de Jussieu, Boîte 186, 4, place Jussieu, 75252 Paris Cedex 05, France
autor
- Analyse Fonctionnelle, Institut de Mathématique de Jussieu, Boîte 186, 4 place Jussieu, F- 75252 Paris Cedex 05, France
Bibliografia
Typ dokumentu
Bibliografia
Identyfikatory
Identyfikator YADDA
bwmeta1.element.bwnjournal-article-doi-10_4064-fm204-3-1