On the -completeness of pseudo MV-algebras
In this paper we investigate the relation between the lattice of varieties of pseudo -algebras and the lattice of varieties of lattice ordered groups.
Several open problems posed during FSTA 2006 (Liptovský Ján, Slovakia) are presented. These problems concern the classification of strict triangular norms, Lipschitz t-norms, interval semigroups, copulas, semicopulas and quasi- copulas, fuzzy implications, means, fuzzy relations, MV-algebras and effect algebras.
Closure -algebras are introduced as a commutative generalization of closure -algebras, which were studied as a natural generalization of topological Boolean algebras.