Results 11 to 20 of about 155 (26)

Permutation of elements in double semigroups [PDF]

, 2015
Double semigroups have two associative operations $\circ, \bullet$ related by the interchange relation: $( a \bullet b ) \circ ( c \bullet d ) \equiv ( a \circ c ) \bullet ( b \circ d )$. Kock \cite{Kock2007} (2007) discovered a commutativity property in
Bremner, Murray, Madariaga, Sara
core   +1 more source

Directed colimits of some flatness properties and purity of epimorphisms in S-posets

Open Mathematics, 2018
Let S be a pomonoid. In this paper, we introduce some new types of epimorphisms with certain purity conditions, and obtain equivalent descriptions of various flatness properties of S-posets, such as strong flatness, Conditions (E), (E′), (P), (Pw), (WP),
Liang Xingliang, Khosravi Roghaieh
doaj   +1 more source

Cross-connections of the singular transformation semigroup [PDF]

, 2017
Cross-connection is a construction of regular semigroups using certain categories called normal categories which are abstractions of the partially ordered sets of principal left (right) ideals of a semigroup.
Muhammed, P. A. Azeef, Rajan, A. R.
core   +1 more source

The algebra of rewriting for presentations of inverse monoids [PDF]

, 2019
We describe a formalism, using groupoids, for the study of rewriting for presentations of inverse monoids, that is based on the Squier complex construction for monoid presentations.
Gilbert, N. D., McDougall, E. A.
core   +2 more sources

A criterion for reflectiveness of normal extensions [PDF]

, 2016
We give a new sufficient condition for the normal extensions in an admissible Galois structure to be reflective. We then show that this condition is indeed fulfilled when X is the (protomodular) reflective subcategory of S-special objects of a Barr-exact
Montoli, Andrea, Rodelo, Diana, Van der Linden, Tim   +2 more
core   +2 more sources

A correspondence between a class of monoids and self-similar group actions II [PDF]

, 2014
The first author showed in a previous paper that there is a correspondence between self-similar group actions and a class of left cancellative monoids called left Rees monoids.
Lawson, Mark V., Wallis, Alistair R.
core   +2 more sources

On finite complete presentations and exact decompositions of semigroups [PDF]

, 2011
We prove that given a finite (zero) exact right decomposition (M, T) of a semigroup S, if M is defined by a finite complete presentation, then S is also defined by a finite complete presentation.
Araújo, João, Malheiro, António
core   +1 more source

A universality result for endomorphism monoids of some ultrahomogeneous structures

, 2011
We devise a fairly general sufficient condition ensuring that the endomorphism monoid of a countably infinite ultrahomogeneous structure (i.e. a Fra\"{\i}ss\'{e} limit) embeds all countable semigroups.
Dolinka, Igor, Mašulović, Dragan
core   +1 more source

On geometrically equivalent S-acts [PDF]

, 2011
In this paper, considering the geometric equivalence for algebras of a variety $_{S}A$ of S-acts over a monoid S, we obtain representation theorems describing all types of the equivalence classes of geometrically equivalent S-acts of varieties $_{S}A ...
Katsov, Yefim
core  

On a generalization of I-regularity

Open Mathematics
Let SS be a pomonoid. The projectivity and strong flatness of right SS-posets have been central topics in the homological classification of pomonoids in recent decades. In 2005, Shi et al. introduced II-regular SS-posets and proved that all its cyclic SS-
Qiao Husheng, Feng Leting
doaj   +1 more source