Overview
In mathematics, a -space is a topological space that satisfies a certain basic selection principle.
An infinite cover of a topological space is an -cover if every finite subset of this space is contained in some member of the cover, and the whole space is not a member the cover. A cover of a topological space is a -cover if every point of this space belongs to all but finitely many members of this cover.
A -space is a space in which every open -cover contains a -cover.
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