Word.ws English Dictionary

extensionality

extensionality noun: the principle that objects are equal if and only if their observed properties are the same, regardless of internal processes that lead to those properties.

Noun

extensionality (usually uncountable, plural extensionalities)

  1. (usually) The principle that objects are equal if and only if their observed properties are the same, regardless of internal processes that lead to those properties.
  2. (usually, functional analysis) The principle that functions are equal if and only if they operate on the same domain and for any given element of the domain the result of each of the functions is the same.
  3. (usually) The principle, codified in the axiom of extensionality, that sets are equal if and only if they contain the same elements.

Forms of extensionality

pluralextensionalities

Origin of extensionality

From extensional + -ity.

Phrases with extensionality

Questions about extensionality

What does extensionality mean?
Extensionality means the principle that objects are equal if and only if their observed properties are the same, regardless of internal processes that lead to those properties.
What part of speech is extensionality?
Extensionality is a noun.
What is the plural of extensionality?
The plural of extensionality is extensionalities.

Words near extensionality in the dictionary

  1. extensionalism
  2. extensionalisms
  3. extensionalist
  4. extensionalists
  5. extensionalities
  6. extensionality
  7. extensionally
  8. extensionist
  9. extensionists
  10. extensionless
  11. extensionlessness

Source and license

Adapted from Wiktionary: extensionality (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

Last updated:

Cite this entry: “extensionality.” Word.ws, https://word.ws/extensionality. Based on Wiktionary, CC BY-SA 4.0.