olemus
erinevuse mõõt matemaatikas
= a measure of dissimilarity in mathematics

(a) lahutamistehte tulem
Wiktionary:
noun
5. (countable) the result of a subtraction; sometimes the absolute value of this result.
The difference between 3 and 21 is 18.
https://www.mathsisfun.com/numbers/images/subtraction.svg

(b) hulkade A ja B vahe:
hulga A kõigi niisuguste elementide hulk, mis ei kuulu hulka B
Wiktionary:
noun
10. (relational algebra) the set of elements that are in one set but not in another
https://en.wikipedia.org/wiki/Complement_(set_theory)#Relative_complement

vt ka
- diferents
- vahe (1)
- vahe (3)