Covering Baire 1 functions with darboux functions and the cofinality of the ideal of meager sets

• Autorzy: Jordan F.
• Języki publikacji: EN

Abstrakty

EN

Let Dar stand for the Darboux Baire class 1 functions. We show that the cofinality of the meager sets in R is the smallest cardinality of a set of Baire class 1 functions F such that for any finite collection of Baire class 1 functions G there is an f ∈ F such that f + G ⊆ Dar. Other results of this type are shown. These results are then considered as statements about additivity. The notion of super-additivity is introduced.

Słowa kluczowe

EN

cardinal functions; meager sets; Baire class 1; extendable functions; connectivity functions; almost continuous functions; Darboux functions

PL

funkcje kardynalne; Baire 1; przedłużenia funkcji; funkcje łączności

• Wydawca: De Gruyter
• Czasopismo: Journal of Applied Analysis
• Rocznik: 1999
• Tom: Vol. 5, nr 1
• Strony: 71--94
• Opis fizyczny: Bibliogr. 18 poz.

Twórcy

autor

Jordan F.

• Department of Mathematics University of Louisville Louisville, KY 40208 USA,