On modular and cancellable elements of the lattice of semigroup varieties
arXiv:1709.02944
Abstract
We completely determine all semigroup varieties satysfiyng a permutational identity of length 3 that are modular elements of the lattice of all semigroup varieties. Using this result, we provide an example of a semigroup variety that is a modular but not cancellable element of this lattice.
12 pages