Axiom of extensionality

Axiom of extensionality - axiom of Zermelo–Fraenkel set theory asserting that set equality is determined by the membership relation. Article “Axiom of extensionality” in English Wikipedia has 35 points for quality (as of July 1, 2025). The article contains 25 references and 8 sections. The article also contains templates indicating quality issues, therefore its score was reduced by 3.88 points.

In this language version of Wikipedia the article has the best quality. Also, this article is the most popular in that (English) language version.

Since the creation of article “Axiom of extensionality”, its content was written by 58 registered users of English Wikipedia and edited by 272 registered Wikipedia users in all languages.

The article is cited 158 times in English Wikipedia and cited 812 times in all languages.

The highest Authors Interest rank from 2001:

• Local (English): #1947 in November 2002
• Global: #4852 in November 2002

The highest popularity rank from 2008:

• Local (English): #416541 in February 2008
• Global: #382579 in April 2015

There are 21 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	English (en) Axiom of extensionality		34.9554
2	Estonian (et) Ekstensionaalsuse aksioom		29.8437
3	Indonesian (id) Aksioma perluasan		22.4723
4	Greek (el) Αξίωμα της επεκτασιμότητας		22.1422
5	Hungarian (hu) Extenzionalitási axióma		19.4625
6	French (fr) Axiome d'extensionnalité		17.0191
7	Polish (pl) Aksjomat ekstensjonalności		16.9021
8	Portuguese (pt) Axioma da extensão		16.8104
9	German (de) Extensionalitätsaxiom		16.5461
10	Chinese (zh) 外延公理		13.6582

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

The most popular language versions of the article "Axiom of extensionality" in all the time

#	Language	Popularity award	Relative popularity
1	English (en) Axiom of extensionality		275 560
2	French (fr) Axiome d'extensionnalité		50 709
3	Russian (ru) Аксиома объёмности		46 067
4	Spanish (es) Axioma de extensionalidad		41 138
5	Polish (pl) Aksjomat ekstensjonalności		37 646
6	Japanese (ja) 外延性の公理		34 880
7	German (de) Extensionalitätsaxiom		28 125
8	Italian (it) Assioma di estensionalità		23 601
9	Chinese (zh) 外延公理		19 666
10	Portuguese (pt) Axioma da extensão		17 031

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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 "Axiom of extensionality" in June 2025

#	Language	Popularity award	Relative popularity
1	English (en) Axiom of extensionality		1 695
2	Japanese (ja) 外延性の公理		390
3	French (fr) Axiome d'extensionnalité		353
4	Russian (ru) Аксиома объёмности		220
5	Polish (pl) Aksjomat ekstensjonalności		107
6	Chinese (zh) 外延公理		94
7	German (de) Extensionalitätsaxiom		84
8	Spanish (es) Axioma de extensionalidad		71
9	Italian (it) Assioma di estensionalità		69
10	Portuguese (pt) Axioma da extensão		54

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

Language versions of the article "Axiom of extensionality" with the highest Authors Interest (number of authors). Only registered Wikipedia users were taken into account.

#	Language	AI award	Relative AI
1	English (en) Axiom of extensionality		58
2	French (fr) Axiome d'extensionnalité		46
3	Italian (it) Assioma di estensionalità		22
4	Persian (fa) اصل موضوع هم‌مصداقی		21
5	Polish (pl) Aksjomat ekstensjonalności		16
6	Russian (ru) Аксиома объёмности		15
7	German (de) Extensionalitätsaxiom		11
8	Chinese (zh) 外延公理		11
9	Spanish (es) Axioma de extensionalidad		9
10	Hungarian (hu) Extenzionalitási axióma		9

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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 "Axiom of extensionality" with the highest AI in June 2025

#	Language	AI award	Relative AI
1	Russian (ru) Аксиома объёмности		1
2	Catalan (ca) Axioma d'extensionalitat		0
3	German (de) Extensionalitätsaxiom		0
4	Greek (el) Αξίωμα της επεκτασιμότητας		0
5	English (en) Axiom of extensionality		0
6	Spanish (es) Axioma de extensionalidad		0
7	Estonian (et) Ekstensionaalsuse aksioom		0
8	Persian (fa) اصل موضوع هم‌مصداقی		0
9	French (fr) Axiome d'extensionnalité		0
10	Hebrew (he) אקסיומת ההיקפיות		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 "Axiom of extensionality" with the highest Citation Index (CI)

#	Language	CI award	Relative CI
1	English (en) Axiom of extensionality		158
2	Portuguese (pt) Axioma da extensão		74
3	Japanese (ja) 外延性の公理		71
4	Chinese (zh) 外延公理		71
5	Russian (ru) Аксиома объёмности		68
6	Ukrainian (uk) Аксіома об'ємності		67
7	Persian (fa) اصل موضوع هم‌مصداقی		61
8	Hebrew (he) אקסיומת ההיקפיות		51
9	French (fr) Axiome d'extensionnalité		38
10	Indonesian (id) Aksioma perluasan		28

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#	Language	Value
ca	Catalan Axioma d'extensionalitat
de	German Extensionalitätsaxiom
el	Greek Αξίωμα της επεκτασιμότητας
en	English Axiom of extensionality
es	Spanish Axioma de extensionalidad
et	Estonian Ekstensionaalsuse aksioom
fa	Persian اصل موضوع هم‌مصداقی
fr	French Axiome d'extensionnalité
he	Hebrew אקסיומת ההיקפיות
hr	Croatian Aksiom rasprostranjenosti
hu	Hungarian Extenzionalitási axióma
id	Indonesian Aksioma perluasan
it	Italian Assioma di estensionalità
ja	Japanese 外延性の公理
nl	Dutch Gelijkheidsaxioma
pl	Polish Aksjomat ekstensjonalności
pt	Portuguese Axioma da extensão
ru	Russian Аксиома объёмности
sv	Swedish Extensionalitetsaxiomet
uk	Ukrainian Аксіома об'ємності
zh	Chinese 外延公理

Best Rank

English: #416541 02.2008

Global: #382579 04.2015

Best Rank

English: #1947 11.2002

Global: #4852 11.2002

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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