the principle that sets are definable in terms of their elements alone, whatever way they may have been selected. Thus {a, b}={b, a}={first two letters of the alphabet}
Examples of 'extensionality' in a sentence
extensionality
We explore this problem from a new angle via the conflict between extensionality and effects.
Philip Johnson-Freyd, Paul Downen, Zena M. Ariola 2016, 'First Class Call Stacks: Exploring Head Reduction', Electronic Proceedings in Theoretical Computer Sciencehttp://arxiv.org/pdf/1606.06378v1. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)