Results 61 to 70 of about 102 (99)

On endomorphisms of power-semigroups

Asian-European Journal of Mathematics, 2017
An involuted semilattice [Formula: see text] is a semilattice [Formula: see text] with an identity element [Formula: see text] and with an involution [Formula: see text] satisfying [Formula: see text] and [Formula: see text]. We consider involuted semilattices [Formula: see text] with an identity [Formula: see text] such that there is a subsemilattice [
Susanti, Yeni, Koppitz, Joerg
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A Functional Equation for the Cosine on Semigroups with Endomorphisms

Vietnam Journal of Mathematics, 2022
Let \(S\) be a semigroup and \(\mathbb{F}\) a quadratically closed field of characteristic different from 2. Assume that \(\phi,\varphi\colon S\to S\) are two given endomorphisms and \(\mu\colon S\to \mathbb{F}\) is a given multiplicative mapping satisfying the condition \(\mu(x\varphi(x))=1\) for all \(x\in S\). Then the functional equation \[ f(x\phi(
Mohamed Ayoubi, Driss Zeglami
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A Note on Endomorphism Semigroups

Canadian Mathematical Bulletin, 1970
If is a universal algebra, the set of endomorphisms of forms a monoid (i.e., semigroup with identity) under composition. We denote it by End (). For definitions and notations, see [1]. It is well known (e.g., [1], Theorem 12.3) that for any monoid M there is a unary algebra with M ≅ End (). E. Mendelsohn and Z.
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Endomorphism Semigroups of Sums of Rings

Canadian Mathematical Bulletin, 1974
Let R= 〈R, +, •〉 be the cartesian sum of the rings Ri, i= 1, 2,…, n denoted by , and recall that R is a ring under the componentwise operations. It is well-known (e.g. [1], p. 212) that the endomorphisms of the group 〈R, + 〉 form a ring HomZR (under function addition and composition) and moreover HomZR is isomorphic to the matrix ring under the usual ...
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Endomorphism monoids in varieties of commutative semigroups

Semigroup Forum, 2013
A characterization of universal varieties of semigroups is given by \textit{V. Koubek} and \textit{J. Sichler} [J. Aust. Math. Soc., Ser. A 36, 143-152 (1984; Zbl 0549.20038)]. Since there are categories that are not universal but close to being universal the notion of almost universality is used.
Demlová, M., Koubek, V., Sichler, J.
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Action of endomorphism semigroups on definable sets

International Journal of Algebra and Computation, 2018
The aim of the paper is to construct, discuss and apply the Galois-type correspondence between subsemigroups of the endomorphism semigroup [Formula: see text] of an algebra [Formula: see text] and sets of logical formulas. Such Galois-type correspondence forms a natural frame for studying algebras by means of actions of different subsemigroups of ...
Grigory Mashevitzky, Boris I. Plotkin, Eugene Plotkin   +2 more
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The semigroup of singular endomorphisms

Semigroup Forum, 1999
Let \(S_n\) denote the set of singular endomorphisms of a vector space \(V\) of dimension \(n\) over a field \(k\). It has long been known that \(S_n\) is an idempotent-generated regular semigroup. The author studies the minimal length of factorization of a given endomorphism \(T\) into a product of idempotents which are alternately \(\mathcal L\)- and
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Endomorphisms of the semigroup of order-preserving mappings

Semigroup Forum, 2010
An endomorphism \(f\) of \(\{1,2,\dots,n\}\) is called order preserving provided that \(i\leq j\) implies \(f(i)\leq f(j)\). The main result of this paper gives a complete classification of the semigroup of all order-preserving endomorphisms of \(\{1,2,\dots,n\}\).
Fernandes, V. H., Jesus, M. M., Maltcev, V., Mitchell, J. D.   +3 more
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Correspondences of the semigroup of endomorphisms of an equivalence relation

Mathematical Notes, 2015
Let \(X\) be an arbitrary nonempty set. A transformation \(\varphi\) of \(X\) is called an endomorphism of a relation \(\rho\subseteq X\times X\) if \((x,y)\in\rho\) implies \((\varphi(x),\varphi (y))\in\rho\) for every \(x,y\in X\). An ordered pair \((\varphi,\psi)\) of transformations of \(X\) is called an endotopism of \(\rho\) if \((x,y)\in\rho ...
Zhuchok, Yu. V., Toichkina, E. A.
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On alternating semigroups of endomorphisms of a groupoid

Matematicheskie Trudy
The bipolar types of composition of a pair of endomorphisms of a groupoid are studied in this work. The notion of an alternating pair of endomorphisms of a groupoid is introduced. For such pairs, a formula is established for calculating the bipolar type of a composition using the bipolar types of endomorphisms included in the composition.
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