Results 11 to 20 of about 138 (31)

On factorisation systems for surjective quandle homomorphisms

, 2014
We study and compare two factorisation systems for surjective homomorphisms in the category of quandles. The first one is induced by the adjunction between quandles and trivial quandles, and a precise description of the two classes of morphisms of this ...
Even, Valérian, Gran, Marino
core   +1 more source

Note on quasivarieties generated by finite pointed abelian groups

Open Mathematics
We prove that a finite pointed abelian group generates a finitely axiomatizable variety that has a finite quasivariety lattice. As a consequence, we obtain that a quasivariety generated by a finite pointed abelian group has a finite basis of quasi ...
Basheyeva Ainur, Lutsak Svetlana
doaj   +1 more source

An embedding theorem for regular Mal'tsev categories

, 2017
In this paper, we obtain a non-abelian analogue of Lubkin's embedding theorem for abelian categories. Our theorem faithfully embeds any small regular Mal'tsev category $\mathbb{C}$ in an $n$-th power of a particular locally finitely presentable regular ...
Jacqmin, Pierre-Alain
core   +1 more source

Theories of analytic monads

, 2012
We characterize the equational theories and Lawvere theories that correspond to the categories of analytic and polynomial monads on Set, and hence also the categories of the symmetric and rigid operads in Set. We show that the category of analytic monads
Burroni, MAREK ZAWADOWSKI, STANISŁAW SZAWIEL   +2 more
core   +1 more source

Star-regularity and regular completions

, 2013
In this paper we establish a new characterisation of star-regular categories, using a property of internal reflexive graphs, which is suggested by a recent result due to O. Ngaha Ngaha and the first author.
Gran, Marino, Janelidze, Zurab
core   +1 more source

On closure operators and reflections in Goursat categories [PDF]

, 2007
By defining a closure operator on effective equivalence relations in a regular category $C$, it is possible to establish a bijective correspondence between these closure operators and the regular epireflective subcategories $L$ of $C$.
Borceux, Francis, Gran, Marino, Mantovani, Sandra   +2 more
core   +2 more sources

A family of varieties of pseudosemilattices

, 2013
In [3], a basis of identities {u_n = v_n | n\geq 2} for the variety SPS of all strict pseudosemilattices was determined. Each one of these identities u_n = v_n has a peculiar 2-content D_n.
Oliveira, Luis
core   +1 more source

On the variety of strict pseudosemilattices

, 2013
A new model, in terms of finite bipartite graphs, of the free pseudosemilattice is presented. This will then be used to obtain several results about the variety SPS of all strict pseudosemilattices: (i) an identity basis for SPS is found, (ii) SPS is ...
Auinger, K., Oliveira, L.
core   +1 more source

Taylor's modularity conjecture and related problems for idempotent varieties

, 2017
We provide a partial result on Taylor's modularity conjecture, and several related problems. Namely, we show that the interpretability join of two idempotent varieties that are not congruence modular is not congruence modular either, and we prove an ...
Opršal, Jakub
core   +1 more source

Exact-$m$-majority terms

, 2022
We say that an idempotent term $t$ is an exact-$m$-majority term if $t$ evaluates to $a$, whenever the element $a$ occurs exactly $m$ times in the arguments of $t$, and all the other arguments are equal.
Lipparini, Paolo
core