Kuratowski's closure-complement problem

Kuratowski's closure-complement problem - theorem that the monoid generated by taking closures and complements of a given set in a topological space has size at most 14, attained by e.g. the set (0, 1) ∪ (1, 2) ∪ {3} ∪ ([4, 5] ∩ ℚ) of reals. Article “Kuratowski's closure-complement problem” in English Wikipedia has 15.2 points for quality (as of July 1, 2025). The article contains 4 references and 4 sections.

This article has the best quality in French Wikipedia. However, this article is the most popular in English version.

Since the creation of article “Kuratowski's closure-complement problem”, its content was written by 22 registered users of English Wikipedia and edited by 44 registered Wikipedia users in all languages.

The article is cited 11 times in English Wikipedia and cited 27 times in all languages.

The highest Authors Interest rank from 2001:

• Local (English): #72224 in October 2022
• Global: #143798 in July 2013

The highest popularity rank from 2008:

• Local (English): #575572 in October 2013
• Global: #950487 in October 2013

There are 6 language versions for this article in the WikiRank database (of the considered 55 Wikipedia language editions).

The quality and popularity assessment was based on Wikipédia dumps from July 1, 2025 (including revision history and pageviews for previous years).

The table below shows the language versions of the article with the highest quality.

#	Language	Quality grade	Quality score
1	French (fr) Théorème de fermeture/complémentaire de Kuratowski		22.0384
2	Korean (ko) 쿠라토프스키 모노이드		19.5152
3	Chinese (zh) 庫拉托夫斯基十四集問題		19.4641
4	English (en) Kuratowski's closure-complement problem		15.2223
5	Arabic (ar) مسألة كوراتويسكي للغلق-التكملة		13.8633
6	Russian (ru) Задача Куратовского		11.16

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The following table shows the most popular language versions of the article.

The most popular language versions of the article "Kuratowski's closure-complement problem" in all the time

#	Language	Popularity award	Relative popularity
1	English (en) Kuratowski's closure-complement problem		68 372
2	Chinese (zh) 庫拉托夫斯基十四集問題		5 378
3	French (fr) Théorème de fermeture/complémentaire de Kuratowski		3 321
4	Russian (ru) Задача Куратовского		2 193
5	Korean (ko) 쿠라토프스키 모노이드		1 233
6	Arabic (ar) مسألة كوراتويسكي للغلق-التكملة		1 081

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The following table shows the language versions of the article with the highest popularity in the last month.

The most popular language versions of the article "Kuratowski's closure-complement problem" in June 2025

#	Language	Popularity award	Relative popularity
1	English (en) Kuratowski's closure-complement problem		354
2	French (fr) Théorème de fermeture/complémentaire de Kuratowski		48
3	Chinese (zh) 庫拉托夫斯基十四集問題		48
4	Russian (ru) Задача Куратовского		30
5	Arabic (ar) مسألة كوراتويسكي للغلق-التكملة		3
6	Korean (ko) 쿠라토프스키 모노이드		0

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The following table shows the language versions of the article with the highest Authors’ Interest.

Language versions of the article "Kuratowski's closure-complement problem" with the highest Authors Interest (number of authors). Only registered Wikipedia users were taken into account.

#	Language	AI award	Relative AI
1	English (en) Kuratowski's closure-complement problem		22
2	French (fr) Théorème de fermeture/complémentaire de Kuratowski		8
3	Chinese (zh) 庫拉托夫斯基十四集問題		8
4	Russian (ru) Задача Куратовского		3
5	Korean (ko) 쿠라토프스키 모노이드		2
6	Arabic (ar) مسألة كوراتويسكي للغلق-التكملة		1

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The following table shows the language versions of the article with the highest Authors’ Interest in the last month.

Language versions of the article "Kuratowski's closure-complement problem" with the highest AI in June 2025

#	Language	AI award	Relative AI
1	Arabic (ar) مسألة كوراتويسكي للغلق-التكملة		0
2	English (en) Kuratowski's closure-complement problem		0
3	French (fr) Théorème de fermeture/complémentaire de Kuratowski		0
4	Korean (ko) 쿠라토프스키 모노이드		0
5	Russian (ru) Задача Куратовского		0
6	Chinese (zh) 庫拉托夫斯基十四集問題		0

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The following table shows the language versions of the article with the highest number of citations.

Language versions of the article "Kuratowski's closure-complement problem" with the highest Citation Index (CI)

#	Language	CI award	Relative CI
1	English (en) Kuratowski's closure-complement problem		11
2	French (fr) Théorème de fermeture/complémentaire de Kuratowski		8
3	Chinese (zh) 庫拉托夫斯基十四集問題		3
4	Arabic (ar) مسألة كوراتويسكي للغلق-التكملة		2
5	Korean (ko) 쿠라토프스키 모노이드		2
6	Russian (ru) Задача Куратовского		1

More...

#	Language	Value
ar	Arabic مسألة كوراتويسكي للغلق-التكملة
en	English Kuratowski's closure-complement problem
fr	French Théorème de fermeture/complémentaire de Kuratowski
ko	Korean 쿠라토프스키 모노이드
ru	Russian Задача Куратовского
zh	Chinese 庫拉托夫斯基十四集問題

Best Rank

English: #575572 10.2013

Global: #950487 10.2013

Best Rank

English: #72224 10.2022

Global: #143798 07.2013

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The WikiRank project is intended for automatic relative evaluation of the articles in the various language versions of Wikipedia. At the moment the service allows to compare over 44 million Wikipedia articles in 55 languages. Quality scores of articles are based on Wikipedia dumps from July, 2025. When calculating current popularity and AI of articles data from June 2025 was taken into account. For historical values of popularity and AI WikiRank used data from 2001 to 2025... More information