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In this paper, we show that the class of representable residuated semigroups has the finite representation property. That is, every finite representable residuated semigroup is isomorphic to some algebra over a finite base. This result…

Logic · Mathematics 2020-12-11 Daniel Rogozin

The symmetry group structures of two dimensional coupled nonlinear Shr\"{o}dinger equations are considered. We first show that the equations admit infinite dimensional symmetry algebra as well as the corresponding symmetry group depending…

Mathematical Physics · Physics 2020-02-13 YueXing Bai , Temuer Chaolu , Yan Li

We will show that almost all nonassociative relation algebras are symmetric and integral (in the sense that the fraction of both labelled and unlabelled structures that are symmetric and integral tends to 1), and using a Fra\"iss\'e limit,…

Logic · Mathematics 2022-02-07 James Koussas

The present paper mainly considers the representation type of the enveloping algebra of monomial algebra. Let $A$ be a monomial algebra and $A^e= A\otimes_{\mathrm{l}\!\mathrm{k}} A^{\mathrm{op}}$ its enveloping algebra. It is shown that…

Representation Theory · Mathematics 2024-04-30 Jianguo Zhou , Yu-Zhe Liu , Chao Zhang

A relation algebra is measurable if the identity element is a sum of atoms, and the square x;1;x of each subidentity atom x is a sum of non-zero functional elements. These functional elements form a group Gx. We prove that a measurable…

Logic · Mathematics 2025-02-12 Hajnal Andréka , Steven Givant

We prove the result in the title. We infer, that unlike cylindric algebras, there is a first order axiomatization of the class of completely representable polyadic algebras of infinite dimension, though the one we obtain is infinite; in…

Logic · Mathematics 2013-06-07 Tarek Sayed Ahmed

We show that, for each finite algebra A, either it has symmetric term operations of all arities or else some finite algebra in the variety generated by A has two automorphisms without a common fixed point. We also show this two-automorphism…

Rings and Algebras · Mathematics 2016-05-16 Catarina Carvalho , Andrei Krokhin

We construct a finite-dimensional metabelian right-symmetric algebra over an arbitrary field that does not have a finite basis of identities.

Rings and Algebras · Mathematics 2024-01-05 Nurlan Ismailov , Ualbai Umirbaev

For finitary regular monads T on locally finitely presentable categories we characterize the finitely presentable objects in the category of T-algebras in the style known from general algebra: they are precisely the algebras presentable by…

Category Theory · Mathematics 2019-09-06 Jiří Adámek , Stefan Milius , Lurdes Sousa , Thorsten Wißmann

A series of nonrepresentable relation algebras is constructed from groups. We use them to prove that there are continuum many subvarieties between the variety of representable relation algebras and the variety of coset relation algebras. We…

Logic · Mathematics 2025-02-12 H. Andréka , S. Givant , I. Németi

Let k be a field. A finite dimensional k-algebra is said to be minimal representation-infinite provided it is representation-infinite and all its proper factor algebras are representation-finite. Our aim is to classify the special biserial…

Representation Theory · Mathematics 2011-02-22 Claus Michael Ringel

We use Monk like algebras to give a new proof that the classes of strongly representable relation algebras and finite dimensional cylindric algebras of dimension >2 are not elementary. Our construction is based on relation algebras have…

Logic · Mathematics 2013-05-21 Tarek Sayed Ahmed

In this paper a characterisation is given of solvable complemented Lie algebras. They decompose as a direct sum of abelian subalgebras and their ideals relate nicely to this decomposition. The class of such algebras is shown to be a…

Rings and Algebras · Mathematics 2011-04-20 David A. Towers

A relation algebra is called measurable when its identity is the sum of measurable atoms, and an atom is called measurable if its square is the sum of functional elements. In this paper we show that atomic measurable relation algebras have…

Logic · Mathematics 2025-02-12 S. Givant , H. Andréka

We find all finite Ockham algebras that admit only finitely many compatible relations (modulo a natural equivalence). Up to isomorphism and symmetry, these Ockham algebras form two countably infinite families: one family consists of the…

Rings and Algebras · Mathematics 2015-01-13 Brian A. Davey , Long T. Nguyen , Jane G. Pitkethly

We assign a relational structure to any finite algebra in a canonical way, using solution sets of equations, and we prove that this relational structure is polymorphism-homogeneous if and only if the algebra itself is…

Logic · Mathematics 2024-02-14 Endre Tóth , Tamás Waldhauser

Several structural properties of a universal algebra can be seen from the higher commutators of its congruences. Even on a finite algebra, the sequence of higher commutator operations is an infinite object. In the present paper, we exhibit…

Rings and Algebras · Mathematics 2022-03-18 Erhard Aichinger , Nebojša Mudrinski

We give complete, finite quasiequational axiomatisations for algebras of unary partial functions under the operations of composition, domain, antidomain, range and intersection. This completes the extensive programme of classifying algebras…

Logic · Mathematics 2014-10-16 Robin Hirsch , Marcel Jackson , Szabolcs Mikulás

The set of linear, differential operators preserving the vector space of couples of polynomials of degrees n and n-2 in one real variable leads to an abstract associative graded algebra A(2). The irreducible, finite dimensional…

solv-int · Physics 2009-10-30 Y. Brihaye , S. Giller , P. Kosinski , J. Nuyts

We exhibit finite cyclic group representations for relation algebras $57_{65}$ and $63_{65}$. As a consequence, of the ten symmetric integral RAs on four atoms having at least one flexible atom, all are now known to have a representation…

Logic · Mathematics 2026-04-07 Jeremy F. Alm