All subvarieties of have finite bases of identities.
All varieties of orthogroups.
Almost associative operations generating a minimal clone
Characterizations of 'almost associative' binary operations generating a minimal clone are given for two interpretations of the term 'almost associative'. One of them uses the associative spectrum, the other one uses the index of nonassociativity to measure how far an operation is from being associative.
Almost direct products and saturation
Almost every tree function is independent
Almost ff-universal and q-universal varieties of modular 0-lattices
A variety 𝕍 of algebras of a finite type is almost ff-universal if there is a finiteness-preserving faithful functor F: 𝔾 → 𝕍 from the category 𝔾 of all graphs and their compatible maps such that Fγ is nonconstant for every γ and every nonconstant homomorphism h: FG → FG' has the form h = Fγ for some γ: G → G'. A variety 𝕍 is Q-universal if its lattice of subquasivarieties has the lattice of subquasivarieties of any quasivariety of algebras of a finite type as the quotient of its sublattice....
Almost orthogonality and Hausdorff interval topologies of atomic lattice effect algebras
We prove that the interval topology of an Archimedean atomic lattice effect algebra is Hausdorff whenever the set of all atoms of is almost orthogonal. In such a case is order continuous. If moreover is complete then order convergence of nets of elements of is topological and hence it coincides with convergence in the order topology and this topology is compact Hausdorff compatible with a uniformity induced by a separating function family on corresponding to compact and cocompact elements....
Amalgamating commutative regular rings
Amalgams of free inverse semigroups.
An algebraic version of the Cantor-Bernstein-Schröder theorem
The Cantor-Bernstein-Schröder theorem of the set theory was generalized by Sikorski and Tarski to -complete boolean algebras, and recently by several authors to other algebraic structures. In this paper we expose an abstract version which is applicable to algebras with an underlying lattice structure and such that the central elements of this lattice determine a direct decomposition of the algebra. Necessary and sufficient conditions for the validity of the Cantor-Bernstein-Schröder theorem for...
An algorithm for free algebras
We present an algorithm for constructing the free algebra over a given finite partial algebra in the variety determined by a finite list of equations. The algorithm succeeds whenever the desired free algebra is finite.
An application of commutator theory to incidence algebras.
Usando la teoria del commutatore in algebra universale, si dimostra che una larga classe di algebre di incidenza sono polinomialmente equivalenti a moduli su anelli con divisione.
An associative operator on the lattice of varieties of inverse semigroups.
An Elementary Characterization of the Category of (Free) Relational Systems.
An elementary characterization of the category of relational systems
An elementary proof that finite groups are projectively torsion-free
An equational basis in four variables for the three-element tournament
An example of the limit variety of semigroups.
An investigation on the -fold IVRL-filters in triangle algebras
The present study aimed to introduce -fold interval valued residuated lattice (IVRL for short) filters in triangle algebras. Initially, the notions of -fold (positive) implicative IVRL-extended filters and -fold (positive) implicative triangle algebras were defined. Afterwards, several characterizations of the algebras were presented, and the correlations between the -fold IVRL-extended filters, -fold (positive) implicative algebras, and the Gödel triangle algebra were discussed.
André-Quillen cohomology for commutative coalgebras