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# extensionality, axiom of

Basic axiom of set theory . It asserts that sets are identical if and only if they have the same members.

Philosophy dictionary. . 2011.

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• extensionality — extensionality, axiom of …   Philosophy dictionary

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• Extensionality — In logic, extensionality refers to principles that judge objects to be equal if they have the same external properties. It is the opposite concept of intensionality, which is concerned with whether two descriptions are intended to be the same or… …   Wikipedia