Results 21 to 30 of about 365 (53)
The Efficiency of the Semi-Direct Products of Free Abelian Monoid with Rank n by the Infinite Cyclic Monoid [PDF]
, 2011 In this paper we give necessary and sufficient conditions for the efficiency of the semi-direct product of free abelian monoid with rank n by the infinite cyclic ...
Ateş, Fırat +2 more
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Associative string functions [PDF]
, 2014 We introduce the concept of associativity for string functions, where a string function is a unary operation on the set of strings over a given alphabet. We discuss this new property and describe certain classes of associative string functions.
Lehtonen, Erkko +2 more
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M\"obius function of semigroup posets through Hilbert series
, 2015 In this paper, we investigate the M{\"o}bius function $\mu\_{\mathcal{S}}$ associated to a (locally finite) poset arising from a semigroup $\mathcal{S}$ of $\mathbb{Z}^m$. We introduce and develop a new approach to study $\mu\_{\mathcal{S}}$ by using the
Alfonsín, Jorge Luis Ramírez +3 more
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Affine semigroups having a unique Betti element
, 2012 We characterize affine semigroups having one Betti element and we compute some relevant non-unique factorization invariants for these semigroups. As an example, we particularize our description to numerical semigroups.Comment: 8 pages, 1 figure.
I. OJEDA +5 more
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Two-sided homological properties of special and one-relator monoids
Forum of Mathematics, SigmaA monoid presentation is called special if the right-hand side of each defining relation is equal to 1. We prove results which relate the two-sided homological finiteness properties of a monoid defined by a special presentation with those of its group of
Robert D. Gray, Benjamin Steinberg
doaj +1 more source
A conjugation-free geometric presentation of fundamental groups of arrangements II: Expansion and some properties [PDF]
, 2011 A conjugation-free geometric presentation of a fundamental group is a presentation with the natural topological generators $x_1, ..., x_n$ and the cyclic relations: $x_{i_k}x_{i_{k-1}} ... x_{i_1} = x_{i_{k-1}} ... x_{i_1} x_{i_k} = ... = x_{i_1} x_{i_k}
Eliyahu, Meital +2 more
core
Length Functions for Semigroup Embeddings [PDF]
, 2010 Following the work done by Olshanskii for groups, we describe, for a given semigroup $S$, which functions $l : S \rightarrow \mathbb{N}$ can be realized up to equivalence as length functions $g \mapsto |g|_{H}$ by embedding $S$ into a finitely generated ...
Davis, Tara
core +2 more sources
, 2012 In this paper we present a new kind of semigroups called convex body semigroups which are generated by convex bodies of R^k. They generalize to arbitrary dimension the concept of proportionally modular numerical semigroup of [7].
A. Sánchez-R.-Navarro +10 more
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Uniquely presented finitely generated commutative monoids
, 2009 A finitely generated commutative monoid is uniquely presented if it has only a minimal presentation. We give necessary and sufficient conditions for finitely generated, combinatorially finite, cancellative, commutative monoids to be uniquely presented ...
Aoki +10 more
core +2 more sources
A Svarc-Milnor lemma for monoids acting by isometric embeddings
, 2010 We continue our programme of extending key techniques from geometric group theory to semigroup theory, by studying monoids acting by isometric embeddings on spaces equipped with asymmetric, partially-defined distance functions.
de la Harpe P. +4 more
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