Special almost P-spaces

Alessandro Fedeli

On relatively almost Lindelöf subsets

Yankui Song (2009)

Mathematica Bohemica

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A subspace $Y$ of a space $X$ is almost Lindelöf (strongly almost Lindelöf) in $X$ if for every open cover $𝒰$ of $X$ (of $Y$ by open subsets of $X$ ), there exists a countable subset $𝒱$ of $𝒰$ such that $Y \subseteq ⋃ {\bar{V} V \in 𝒱}$ . In this paper we investigate the relationships between relatively almost Lindelöf subset and relatively strongly almost Lindelöf subset by giving some examples, and also study various properties of relatively almost Lindelöf subsets and relatively strongly almost Lindelöf subsets.

On $ω^{2}$ -saturated families

Lajos Soukup (1991)

Commentationes Mathematicae Universitatis Carolinae

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If there is no inner model with measurable cardinals, then for each cardinal $λ$ there is an almost disjoint family $𝒜_{λ}$ of countable subsets of $λ$ such that every subset of $λ$ with order type $\geq ω^{2}$ contains an element of $𝒜_{λ}$ .

Displaying similar documents to “Special almost P-spaces”

On relatively almost Lindelöf subsets

On ω 2 -saturated families

On $ω^{2}$ -saturated families