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first-countable space

topological space in which every point admits a countable neighborhood basis
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first-countable space

Summary

first-countable space ranks in the top 2% of general entities by monthly Wikipedia readership (70 views/month).[1]

Key Facts

  • first-countable space's subclass of is recorded as topological space[2].
  • first-countable space's Freebase ID is recorded as /m/03nkwz[3].
  • first-countable space's defining formula is recorded as \forall x\in X\exists\mathcal B\subset\mathcal N_x\colon|\mathcal B|\le\aleph_0\land\forall N\in\mathcal N_x\exists B\in\mathcal B\colon B\subset N[4].
  • first-countable space's BabelNet ID is recorded as 03797197n[5].
  • first-countable space's MathWorld ID is recorded as First-CountableSpace[6].
  • first-countable space's JSTOR topic ID is recorded as first-countable[7].
  • first-countable space's nLab ID is recorded as first-countable space[8].
  • first-countable space's maintained by WikiProject is recorded as WikiProject Mathematics[9].
  • first-countable space's Microsoft Academic ID is recorded as 118630013[10].
  • first-countable space's ProofWiki ID is recorded as Definition:First-Countable_Space[11].
  • first-countable space's in defining formula is recorded as X[12].
  • first-countable space's in defining formula is recorded as \mathcal N_x[13].
  • first-countable space's in defining formula is recorded as \aleph_0[14].
  • first-countable space's in defining formula is recorded as N[15].
  • first-countable space's in defining formula is recorded as \land[16].
  • first-countable space's Encyclopedia of Mathematics article ID is recorded as First_axiom_of_countability[17].
  • first-countable space's PlanetMath ID is recorded as FirstCountable[18].
  • first-countable space's PlanetMath ID is recorded as FirstAxiomOfCountability[19].
  • first-countable space's Metamath statement ID is recorded as df-1stc[20].

Why It Matters

first-countable space ranks in the top 2% of general entities by monthly Wikipedia readership (70 views/month).[1] It has Wikipedia articles in 10 language editions, a strong signal of global cultural recognition.[21] It is known by 9 alternative names across languages and contexts.[22]

References

Programmatic citations — every numbered marker resolves to a verifiable graph row below.

Direct Wikidata claims

  1. [2] ↑ . wikidata.org.
  2. [3] ↑ . Freebase Data Dumps. wikidata.org.
  3. [4] ↑ . wikidata.org.
  4. [5] ↑ . BabelNet. wikidata.org.
  5. [6] ↑ . wikidata.org.
  6. [7] ↑ . wikidata.org.
  7. [8] ↑ . wikidata.org.
  8. [9] ↑ . wikidata.org.
  9. [10] ↑ . wikidata.org.
  10. [11] ↑ . wikidata.org.
  11. [12] ↑ . wikidata.org.
  12. [13] ↑ . wikidata.org.
  13. [14] ↑ . wikidata.org.
  14. [15] ↑ . wikidata.org.
  15. [16] ↑ . wikidata.org.
  16. [17] ↑ . wikidata.org.
  17. [18] ↑ . wikidata.org.
  18. [19] ↑ . wikidata.org.
  19. [20] ↑ . wikidata.org.

Aggregate / graph-position facts

  1. [1] ↑ . Wikimedia Foundation. dumps.wikimedia.org.
  2. [21] ↑ . Wikidata sitelinks. wikidata.org.
  3. [22] ↑ . Wikidata aliases. wikidata.org.

📑 Cite this page

Use these citations when quoting this entity in research, articles, AI prompts, or wherever provenance matters. We aggregate Wikidata + Wikipedia + authoritative open-data sources; the stitched, scored, cross-referenced view is what 4ort.xyz contributes.

APA 4ort.xyz Knowledge Graph. (2026). first-countable space. Retrieved April 10, 2026, from https://4ort.xyz/entity/first-countable-space
MLA “first-countable space.” 4ort.xyz Knowledge Graph, 4ort.xyz, 10 Apr. 2026, https://4ort.xyz/entity/first-countable-space.
BibTeX @misc{4ortxyz_first-countable-space_2026, author = {{4ort.xyz Knowledge Graph}}, title = {{first-countable space}}, year = {2026}, url = {https://4ort.xyz/entity/first-countable-space}, note = {Accessed: 2026-04-10}}
LLM prompt According to 4ort.xyz Knowledge Graph (aggregator of Wikidata, Wikipedia, and authoritative open-data sources): first-countable space — https://4ort.xyz/entity/first-countable-space (retrieved 2026-04-10)

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