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Let X be an affine variety and L be a solvable Lie subalgebra of Lie(Aut(X)) generated by a finite collection of locally finite Lie subalgebras. The authors of [arXiv:2507.09679] wondered whether L is itself locally finite. Here we present…

Algebraic Geometry · Mathematics 2026-05-26 Mikhail Zaidenberg

The finite basis property is often connected with the finite rank property, which it entails. Many examples have been produced of finite rank varieties which are not finitely based. In this note, we establish a result on nilpotent…

Group Theory · Mathematics 2019-03-18 J. Almeida , M. H. Shahzamanian

Profinite semigroups are a generalization of finite semigroups that come about naturally when one is interested in considering free structures with respect to classes of finite semigroups. They also appear naturally through dualization of…

Group Theory · Mathematics 2018-04-24 Jorge Almeida , Alfredo Costa

We prove that a commutative parasemifield S is additively idempotent provided that it is finitely generated as a semiring. Consequently, every proper commutative semifield T that is finitely generated as a semiring is either additively…

Commutative Algebra · Mathematics 2019-10-08 Vítězslav Kala , Miroslav Korbelář

For an element a in a semigroup S the local subsemigroup of S with respect to a is the subsemigroup aSa of S and the variant of S with respect to a is a semigroup with underlying set S with a sandwich operation xy = xay for all x, y in S.…

Group Theory · Mathematics 2019-10-31 Siji Michael , P. G. Romeo

Among cocomplete categories, the locally presentable ones can be defined as those with a strong generator consisting of presentable objects. Assuming Vop{\v{e}}nka's Principle, we prove that a cocomplete category is locally presentable iff…

Category Theory · Mathematics 2020-12-04 J. Adámek , A. Brooke-Taylor , T. Campion , L. Positselski , J. Rosický

We show that every definable subset of an uncountably categorical pseudofinite structure has pseudofinite cardinality which is polynomial (over the rationals) in the size of any strongly minimal subset, with the degree of the polynomial…

Logic · Mathematics 2025-02-05 Alexander Van Abel

In this work, the lattice of varieties of semigroups and the lattice of varieties of I-semigroups (a common setting for both the variety of completely regular semigroups and the variety of inverse semigroups) are studied with respect to the…

Group Theory · Mathematics 2016-06-14 Pedro V. Silva , Filipa Soares

We provide algorithms for performing computations in generalized numerical semigroups, that is, submonoids of $\mathbb{N}^{d}$ with finite complement in $\mathbb{N}^{d}$. These semigroups are affine semigroups, which in particular implies…

Combinatorics · Mathematics 2019-11-22 Carmelo Cisto , Manuel Delgado , Pedro A. García-Sánchez

The concept of an omnigenous locally finite group was introduced in [2] as a generalization of Hall's universal countable locally finite group. In this paper we show that the class of all countable omnigenous locally finite groups is Borel…

Logic · Mathematics 2025-09-17 Su Gao , Feng Li

We show every locally solvable subgroup of PLo(I) is countable. A corollary is that an uncountable wreath product of copies of $\mathbb{Z}$ with itself does not embed into PLo(I).

Group Theory · Mathematics 2018-05-23 Amanda Taylor

Let G be a locally compact Hausdorff group in which every element is of finite order, and let P(G) denote the class of all regular probability measures on G. In this note, it is observed that a characterization of algebraically regular…

Functional Analysis · Mathematics 2026-03-20 M N N Namboodiri

We prove that two countable locally finite-by-abelian groups G,H endowed with proper left-invariant metrics are coarsely equivalent if and only if their asymptotic dimensions coincide and the groups are either both finitely-generated or…

Group Theory · Mathematics 2008-09-30 T. Banakh , J. Higes , I. Zarichinyy

We investigate whether semigroups with a given property which are also locally embeddable into finite semigroups can be locally embedded into finite semigroups with the same property, obtaining a positive answer for completely simple and…

Group Theory · Mathematics 2025-10-27 Dmitry Kudryavtsev

We study systematically groups whose marked finite quotients form a recursive set. We give several definitions, and prove basic properties of this class of groups, and in particular emphasize the link between the growth of the depth…

Group Theory · Mathematics 2021-10-27 Emmanuel Rauzy

Locality semigroups were proposed recently as one of the basic locality algebraic structures, which are studied in mathematics and physics. Path semigroups and partial semigroups were also developed by many authors in the literature. In…

Rings and Algebras · Mathematics 2018-09-06 Shanghua Zheng

Graduated locally finitely presentable categories are introduced, examples include categories of sets, vector spaces, posets, presheaves and Boolean algebras. A finitary functor between graduated locally finitely presentable categories is…

Category Theory · Mathematics 2024-02-06 Jirí Adámek , Lurdes Sousa

We study the existence of uncountable first-order structures that are homogeneous with respect to their finitely generated substructures. In many classical cases this is either well-known or follows from general facts, for example, if the…

Logic · Mathematics 2025-10-21 Adam Bartoš , Wiesław Kubiś

We consider implicit signatures over finite semigroups determined by sets of pseudonatural numbers. We prove that, under relatively simple hypotheses on a pseudovariety V of semigroups, the finitely generated free algebra for the largest…

Group Theory · Mathematics 2023-06-22 J. Almeida , J. C. Costa , M. Zeitoun

We establish that, under certain closure assumptions on a pseudovariety of semigroups, the corresponding relatively free profinite semigroups freely generated by a non-singleton finite set act faithfully on their minimum ideals. As…

Group Theory · Mathematics 2020-09-15 J. Almeida , O. Klíma