Sequential + separable vs sequentially separable and another variation on selective separability

• Autorzy: Angelo Bella , Maddalena Bonanzinga , Mikhail Matveev
• Języki publikacji: EN

Abstrakty

EN

A space X is sequentially separable if there is a countable D ⊂ X such that every point of X is the limit of a sequence of points from D. Neither “sequential + separable” nor “sequentially separable” implies the other. Some examples of this are presented and some conditions under which one of the two implies the other are discussed. A selective version of sequential separability is also considered.

Słowa kluczowe

EN

Sequential space; Separable space; Sequentially separable space; Strongly sequentially separable space; Selective separability

Kategorie tematyczne

• 54D65: Separability
• 54A20: Convergence in general topology (sequences, filters, limits, convergence spaces, etc.)
• 54A25: Cardinality properties (cardinal functions and inequalities, discrete subsets)
• 54D55: Sequential spaces

• Wydawca: De Gruyter Open
• Czasopismo: Open Mathematics
• Rocznik: 2013
• Tom: 11
• Numer: 3
• Strony: 530-538

Daty

wydano

2013-03-01

online

2012-12-22

Twórcy

autor

Angelo Bella

• Dipartimento di Matematica, Cittá Universitaria, Viale A. Doria 6, 98125, Catania, Italy

autor

Maddalena Bonanzinga

• Dipartimento di Matematica, Università di Messina, Viale F. Stagno d’Alcontres 31, 98166, Messina, Italy

autor

Mikhail Matveev

Bibliografia

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Identyfikatory

DOI

10.2478/s11533-012-0140-5