All a b c d e f g h i j k l m n o p q r s t u v w x y z Other

Previous Page 4 Next

Displaying 61 – 80 of 141

Showing per page

Some conditions under which a uniform space is fine

Umberto Marconi (1993)

Commentationes Mathematicae Universitatis Carolinae

Let X be a uniform space of uniform weight μ . It is shown that if every open covering, of power at most μ , is uniform, then X is fine. Furthermore, an ω μ -metric space is fine, provided that every finite open covering is uniform.

Some new versions of an old game

Vladimir Vladimirovich Tkachuk (1995)

Commentationes Mathematicae Universitatis Carolinae

The old game is the point-open one discovered independently by F. Galvin [7] and R. Telgársky [17]. Recall that it is played on a topological space X as follows: at the n -th move the first player picks a point x n ∈ X and the second responds with choosing an open U n ∋ x n . The game stops after ω moves and the first player wins if ∪ { U n : n ∈ ω } = X . Otherwise the victory is ascribed to the second player. In this paper we introduce and study the games θ and Ω . In θ the moves are made exactly as in the point-open game, but the...

Some non-multiplicative properties are l -invariant

Vladimir Vladimirovich Tkachuk (1997)

Commentationes Mathematicae Universitatis Carolinae

A cardinal function ϕ (or a property 𝒫 ) is called l -invariant if for any Tychonoff spaces X and Y with C p ( X ) and C p ( Y ) linearly homeomorphic we have ϕ ( X ) = ϕ ( Y ) (or the space X has 𝒫 ( ≡ X ⊢ 𝒫 ) iff Y ⊢ 𝒫 ). We prove that the hereditary Lindelöf number is l -invariant as well as that there are models of Z F C in which hereditary separability is l -invariant.

Some properties of g- and P-spaces

Kalamidas, N. (1999)

Serdica Mathematical Journal

A γ-space with a strictly positive measure is separable. An example of a non-separable γ−space with c.c.c. is given. A P−space with c.c.c. is countable and discrete.

Currently displaying 61 – 80 of 141