olemus
kontekstist sõltuv muutumatu olem

(1) matemaatikas:
objekti atribuut, mis säilib mingi teisenduste klassi korral
= an attribute of a mathematical object which remains unchanged after operations or transformations of a certain type
https://en.wikipedia.org/wiki/Invariant_(mathematics)
https://en.wikipedia.org/wiki/Invariant_theory
http://www.diva-portal.org/smash/get/diva2:1072746/FULLTEXT01.pdf
näide:
geomeetrilise kujundi pindala on isomeetriate suhtes invariant

(2) arvutialal
avaldis, mille väärtus ei muutu programmi(osa) töötamise kestel
= an expression whose value doesn't change during program execution
näiteid:
https://en.wikipedia.org/wiki/Class_invariant
https://en.wikipedia.org/wiki/Loop_invariant
https://medium.com/code-design/invariants-in-code-design-557c7864a047

vt ka
- invariantskeem