The article gives an overview of the main known results on closed classes in partial k-valued logic. The main emphasis is on intervals of closed classes in partial k-valued logic, generated by some closed class A in the set of everywhere defined k-valued functions. Results on Lau intervals are presented, as well as recent results on intervals Int(A) introduced by the author. Some results are given with full proofs.

k-valued logic, partial k-valued logic, closed class, clone

Mathematical problems and theory of numerical methods

Alekseev Valerii Borisovich,  vbalekseev@rambler.ru,  Lomonosov Moscow State University