On Klein Surfaces and Dihedral Groups.
On Konieczny's conjecture of Boolean matrices.
On Kurosh-Amitsur radicals of finite groups.
On la-semigroup defined by a commutative inverse semigroup
On lattice automorphisms of the special linear group
We show, with a counterexample, that proposition 3 in [2], as it stands, is not correct; we prove however that by changing the hypothesis the thesis of the proposition remains still valid.
On lattice ordered periodic semigroups
On lattice properties of S-permutably embedded subgroups of finite soluble groups
In this paper we prove the following results. Let π be a set of prime numbers and G a finite π-soluble group. Consider U, V ≤ G and such that and . Suppose also is a Hall π-sub-group of some S-permutable subgroup of G. Then and . Therefore,the set of all S-permutably embedded subgroups of a soluble group G into which a given Hall system Σ reduces is a sublattice of the lattice of all Σ-permutable subgroups of G. Moreover any two subgroups of this sublattice of coprimeorders permute.
On lattices embeddable into subsemigroup lattices. III: Nilpotent semigroups.
On left absolutely flat monoids.
On left --liberal semigroups
In this paper the equivalence on a semigroup in terms of a set of idempotents in is defined. A semigroup is called a -liberal semigroup with as the set of projections and denoted by if every -class in it contains an element in . A class of -liberal semigroups is characterized and some special cases are considered.
On left canellative semigroups.
On left distributive left idempotent groupoids
We study the groupoids satisfying both the left distributivity and the left idempotency laws. We show that they possess a canonical congruence admitting an idempotent groupoid as factor. This congruence gives a construction of left idempotent left distributive groupoids from left distributive idempotent groupoids and right constant groupoids.
On left, right and two-sided cancellable elements of semigroups.
On Levi quasivarieties generated by nilpotent groups.
On lexico extensions of lattice ordered groups
On L-Groups.
On Lie algebroid actions and morphisms
On Lie powers of regular modules in characteristic 2
On Lie semiheaps and ternary principal bundles
We introduce the notion of a Lie semiheap as a smooth manifold equipped with a para-associative ternary product. For a particular class of Lie semiheaps we establish the existence of left-invariant vector fields. Furthermore, we show how such manifolds are related to Lie groups and establish the analogue of principal bundles in this ternary setting. In particular, we generalise the well-known ‘heapification’ functor to the ambience of Lie groups and principal bundles.
On limit sets of geometrically finite Kleinian groups.