Definition:Point Finite
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Definition
Let $S$ be a set.
Let $\CC$ be a set of subsets of $S$.
Then $\CC$ is point finite if and only if each element of $S$ is an element of finitely many sets in $\CC$:
- $\forall s \in S: \card {\set {C \in \CC: s \in C} } < \infty$
Also defined as
Some sources define point finite only for subsets of topological spaces.
Others define point finite only for covers.
In each case, however, the underlying meaning is identical.
Also see
Sources
- 1955: John L. Kelley: General Topology: Chapter $5$: Problem $\text{V}$
- 1978: Lynn Arthur Steen and J. Arthur Seebach, Jr.: Counterexamples in Topology (2nd ed.) ... (previous) ... (next): Part $\text I$: Basic Definitions: Section $3$: Compactness: Paracompactness
- 2000: James R. Munkres: Topology (2nd ed.): Exercise $39.2$