Countability of the Set of Closed Overclasses of Some Minimal Classes in the Partly Ordered Set {\mathfrak{\cal L}}^{3}_{2} of All Closed Classes of Three-Valued Logic that Can be Mapped Homomorphically onto Two-Valued Logic / A. V. Makarov and V. V. Makarov. // Vestnik Moskovskogo Universiteta. Seriya 1. Matematika. Mekhanika. 2017. № 1. P. 62-64
[Moscow Univ. Math. Bulletin. Vol. 72, N 2, 2017. P. 35-36].
The following theorem is proved: the set of closed classes containing some minimal classes in the partly
ordered set {\mathfrak{\cal L}}^{3}_{2} of closed classes in the three-valued logic
that may be mapped homomorphically onto the two-valued logic is countable.