Compactness (mathematics)

topological space in which from every open cover of the space, a finite cover can be extracted

topological space such that every open cover has a countable subcover

topological space such that every point has a neighbourhood with compact closure

type of continuous linear operator

topological space in which every open cover has an open refinement that is locally finite

uniform space which has finite covers consisting of "arbitrarily small" sets

Topological space where every sequence has a convergent subsequence.

subset of a topological space whose closure is compact

union of countably many compact topological spaces

topological space in which from every countable open cover of the space, a finite cover can be extracted

topological space that admits a sequence of compact subsets such that every compact subset of the space lies inside some compact set in the sequence

topological space with a point-finite open refinement for every cover