16 citations · 102 across the 23 of their papers we have counts for
4 papers · 2 filters
The lattice of varieties of monoids
Sergey V. Gusev, Edmond W. H. Lee, Boris M. Vernikov
We survey results devoted to the lattice of varieties of monoids. Along with known results, some unpublished results are given with proofs. A number of open questions and problems…
Two weaker variants of congruence permutability for monoid varieties
Sergey V. Gusev, Boris M. Vernikov
We completely determine all varieties of monoids on whose free objects all fully invariant congruences or all fully invariant congruences contained in the least semilattice congrue…
Classification of limit varieties of J-trivial monoids
S. V. Gusev, O. B. Sapir
A variety of algebras is called limit if it is non-finitely based but all its proper subvarieties are finitely based. We present a new pair of limit varieties of monoids and show t…
Varieties of monoids with complex lattices of subvarieties
Sergey V. Gusev, Edmond W. H. Lee
A variety is finitely universal if its lattice of subvarieties contains an isomorphic copy of every finite lattice. Examples of finitely universal varieties of semigroups have been…