Results 81 to 90 of about 1,047,734 (218)
, 2012 In this thesis we consider in detail the following two fundamental problems for semigroup presentations: 1. Given a semigroup find a presentation defining it. 2. Given a presentation describe the semigroup defined by it.
Ruškuc, Nik
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Context‐free graphs and their transition groups
Transactions of the London Mathematical Society, Volume 13, Issue 1, December 2026.Abstract Starting from context‐free inverse graphs, we introduce a new class of groups and study their structural properties. We establish closure properties, show that their coword problems are context‐free, analyze torsion elements, and realize them as subgroups of the asynchronous rational group.
Daniele D'Angeli +3 more
wiley +1 more source
The regular radical of semigroup rings of commutative semigroups [PDF]
Glasgow Mathematical Journal, 1992 A description of regular group rings is well known (see [12]). Various authors have considered regular semigroup rings (see [17], [8], [10], [11], [4]). These rings have been characterized for many important classes of semigroups, although the general problem turns out to be rather difficult and still has not got a complete solution.
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Proper affine deformations of positive representations
Journal of Topology, Volume 19, Issue 4, December 2026.Abstract We define, for every positive Anosov representation of a nonabelian free group into SO(2n,2n−1)$\mathrm{SO}(2n,2n-1)$, a family of R4n−1$\mathbb {R}^{4n-1}$‐valued cocycles which induce proper affine actions on R4n−1$\mathbb {R}^{4n-1}$. We construct fundamental domains in R4n−1$\mathbb {R}^{4n-1}$ bounded by generalized crooked planes for ...
Jean‐Philippe Burelle +1 more
wiley +1 more source
On regular and intra-regular poe-semigroups
Semigroup Forum, 1984 This note follows a long series of papers of the same author on regular poe-semigroups [see e.g. ibid. 19, 111-121 (1980; Zbl 0434.06015); 23, 85-86 (1981; Zbl 0467.06010); 25, 213-222 (1982; Zbl 0499.06012); 28, 371-372 (1984; Zbl 0534.06006)]. The author establishes a characterization of le-semigroups which are intra-regular and of the intra-regular ...
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On fuzzy soft bi-ideals over semigroups [PDF]
Songklanakarin Journal of Science and Technology (SJST), 2015 The aim of this paper is to study fuzzy soft bi-ideals over semigroups and give some properties of prime, strongly prime and semiprime fuzzy soft bi-ideals over semigroups.
Manoj Siripitukdet, Peerapong Suebsan
doaj
Weighted veronese rings via convex semigroups
Bulletin of the London Mathematical Society, Volume 58, Issue 11, November 2026.Abstract We determine several properties of two‐dimensional normal affine semigroup rings, and in particular of weighted Veronese rings, including determinantal presentations, Gröbner bases, graded Hilbert series and graded Betti numbers, the structure of their associated graded rings, and their Koszul property.
Bek Chase +6 more
wiley +1 more source
, 2016 <p>The <strong>Semigroups</strong> package is a <strong>GAP</strong> package containing methods for semigroups, monoids, and inverse semigroups, principally of transformations, partial permutations, bipartitions ...
Pfeiffer, Markus +21 more
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On maximal subgroups of free idempotent generated semigroups [PDF]
, 2011 We prove the following results: (1) Every group is a maximal subgroup of some free idempotent generated semigroup. (2) Every finitely presented group is a maximal subgroup of some free idempotent generated semigroup arising from a finite semigroup.
Ruskuc, N. +6 more
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On the structure of semigroups whose regular elements are completely regular
, 2023 International audienceWe study the structure of strongly 2-chained semigroups, which can be defined alternatively as semigroups whose regular elements are completely regular.
Mary, Xavier
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