Varieties generated by semigroups of order four.
Varieties of abelian quasigroups
Varieties of completely regular semigroups generated by Mal'cev products.
Varieties of finite categories
Varieties of generalized Lie groups
Varieties of groupoids associated with involuted restrictive bisemigroups of binary relations.
Varieties of groupoids determined by short linear identities
Varieties of half lattice-ordered groups of monotonic permutations of chains
Varieties of idempotent commutative groupoids
Varieties of idempotent groupoids with small clones
We give an equational description of all idempotent groupoids with at most three essentially n-ary term operations.
Varieties of idempotent medial n-quasigroups
Varieties of idempotent slim groupoids
Idempotent slim groupoids are groupoids satisfying and . We prove that the variety of idempotent slim groupoids has uncountably many subvarieties. We find a four-element, inherently nonfinitely based idempotent slim groupoid; the variety generated by this groupoid has only finitely many subvarieties. We investigate free objects in some varieties of idempotent slim groupoids determined by permutational equations.
Varieties of Lattice-Ordered Groups.
Varieties of left distributive semigroups
Varieties of operator semigroups representing partitions.
Varieties of quasigroups determined by short strictly balanced identities
Varieties of Topological Groups Generated by Groups with Invariant Compact Neighbourhoods of the Identity
Varieties of topological groups generated by maximally almost periodic groups
Varieties preserved under wreath products.
Varieties with modular and distributive lattices of symmetric or reflexive relations