Results 1 to 10 of about 233 (46)
Singly generated quasivarieties and residuated structures [PDF]
, 2019 A quasivariety K of algebras has the joint embedding property (JEP) iff it is generated by a single algebra A. It is structurally complete iff the free countably generated algebra in K can serve as A.
Anderson A. R. +25 more
core +2 more sources
The possible values of critical points between strongly congruence-proper varieties of algebras [PDF]
, 2014 We denote by Conc(A) the semilattice of all finitely generated congruences of an (universal) algebra A, and we define Conc(V) as the class of all isomorphic copies of all Conc(A), for A in V, for any variety V of algebras.
Elliott +24 more
core +3 more sources
Radicals of 0-regular algebras [PDF]
, 2006 We consider a generalisation of the Kurosh--Amitsur radical theory for rings (and more generally multi-operator groups) which applies to 0-regular varieties in which all operations preserve 0.
McConnell, N. R., Stokes, Tim E.
core +1 more source
Admissibility in Finitely Generated Quasivarieties [PDF]
, 2013 Checking the admissibility of quasiequations in a finitely generated (i.e., generated by a finite set of finite algebras) quasivariety Q amounts to checking validity in a suitable finite free algebra of the quasivariety, and is therefore decidable ...
Metcalfe, George +1 more
core +4 more sources
Admissibility via Natural Dualities [PDF]
, 2015 It is shown that admissible clauses and quasi-identities of quasivarieties generated by a single finite algebra, or equivalently, the quasiequational and universal theories of their free algebras on countably infinitely many generators, may be ...
Cabrer, Leonardo Manuel +1 more
core +3 more sources
The Relatively Free Groups F(Nc∧A2) Satisfy Noncentral Commutative Transitivity
Algebra, Volume 2014, Issue 1, 2014., 2014 We prove that a free group, F(Nc∧A2), relative to the variety, Nc∧A2, of all groups simultaneously nilpotent of class at most c and metabelian is such that the centralizer of every noncentral element is abelian. We relate that result to the model theory of such groups as well as a quest to find a relative analog in Nc∧A2 of a classical theorem of ...
Anthony M. Gaglione +3 more
wiley +1 more source
A notion of functional completeness for first‐order structure
International Journal of Mathematics and Mathematical Sciences, Volume 2005, Issue 14, Page 2207-2215, 2005., 2005 Using ☆‐congruences and implications, Weaver (1993) introduced the concepts of prevariety and quasivariety of first‐order structures as generalizations of the corresponding concepts for algebras. The notion of functional completeness on algebras has been defined and characterized by Burris and Sankappanavar (1981), Kaarli and Pixley (2001), Pixley ...
Etienne R. Alomo Temgoua, Marcel Tonga
wiley +1 more source
Varieties of distributive rotational lattices [PDF]
, 2013 A rotational lattice is a structure (L;\vee,\wedge, g) where L=(L;\vee,\wedge) is a lattice and g is a lattice automorphism of finite order. We describe the subdirectly irreducible distributive rotational lattices.
A.H. Clifford +14 more
core +2 more sources
The algebra of adjacency patterns: Rees matrix semigroups with reversion [PDF]
, 2009 We establish a surprisingly close relationship between universal Horn classes of directed graphs and varieties generated by so-called adjacency semigroups which are Rees matrix semigroups over the trivial group with the unary operation of reversion.
D.M. Clark +18 more
core +2 more sources
The Largest Subsemilattices of the Endomorphism Monoid of an Independence Algebra [PDF]
, 2014 An algebra $\A$ is said to be an independence algebra if it is a matroid algebra and every map $\al:X\to A$, defined on a basis $X$ of $\A$, can be extended to an endomorphism of $\A$.
Araújo, João +2 more
core +2 more sources