Let V be a variety of algebras. We establish a condition equivalent to the fact that for each algebra A in V, the set of all subalgebras of A is a subuniverse of the complex algebra of subsets. (en)
Dlja mnogoobrazia algebr V, dajom uslovije kotoroje ekvivalentno tomu, čto podalgebry každoj algebry A v V obrazujut poduniversum algebry podmnožestv A.