IMI/Publicaţii/BASM/Ediţii/BASM n.4 (10), 1992/

Solution of the problem of completeness with respect to expressibility in a $5$-valued nonchain extension of duality intuitionistic logic. (Russian)

Authors: Gkhaliekh Ya. H., Ratsa M. F.


The duality intuitioniste logic has been constructed in the works of G.C.~Moisil and A.V.~Cuznetsov on the basis of intuitioniste propozitional logic to enrich it with duality operaters and with duality rule. The necessity and sufficient conditions for expressibility of all formulae in the logic of 5-valued distributive lattice with two atoms are found here. There is a discription of 20 originaly pre-complete classes of formulae in the paper.