Countability of the set of closed overclasses of some minimal classes in the partly ordered set ℒ2 3 of all closed classes of three-valued logic that can be mapped homomorphically onto two-valued logic
А.В. Макаров, V. V. Makarov · Moscow University Mathematics Bulletin · 2017
The following theorem is proved: the set of closed classes containing some minimal classes in the partly ordered set ℒ2 3 of closed classes in the three-valued logic that may be mapped homomorphically onto the two-valued logic is countable.