Results 1 to 10 of about 198 (35)
Join Irreducible 2-Testable Semigroups
Discussiones Mathematicae - General Algebra and Applications, 2021 A nontrivial pseudovariety is join irreducible if whenever it is contained in the complete join of some collection of pseudovarieties, then it is contained in one of the pseudovarieties.
Lee Edmond W.H.
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Green’s Relations on Submonoids of Generalized Hypersubstitutions of Type (n)
Discussiones Mathematicae - General Algebra and Applications, 2021 A generalized hypersubstitution of type τ = (n) is a function which takes the n-ary operation symbol f to the term of the same type σ(f ) which does not necessarily preserve the arity. Let HypG(n) be the set of all these generalized hypersubstitutions of
Kunama Pornpimol, Leeratanavalee Sorasak
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Factoriality and the Pin-Reutenauer procedure [PDF]
Discrete Mathematics & Theoretical Computer Science, 2016 We consider implicit signatures over finite semigroups determined by sets of pseudonatural numbers. We prove that, under relatively simple hypotheses on a pseudovariety V of semigroups, the finitely generated free algebra for the largest such signature ...
J. Almeida, J. C. Costa, M. Zeitoun
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On the insertion of n-powers [PDF]
Discrete Mathematics & Theoretical Computer Science, 2019 In algebraic terms, the insertion of $n$-powers in words may be modelled at the language level by considering the pseudovariety of ordered monoids defined by the inequality $1\le x^n$.
J. Almeida, O. Klíma
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Chains and anti-chains in the lattice of epigroup varieties [PDF]
, 2009 Let $\mathcal E_n$ be the variety of all epigroups of index $\le n$. We prove that, for an arbitrary natural number $n$, the interval $[\mathcal E_n, \mathcal E_{n+1}]$ of the lattice of epigroup varieties contains a chain isomorphic to the chain of real
Skokov, D. V., Vernikov, B. M.
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Special elements of the lattice of monoid varieties [PDF]
, 2017 We completely classify all neutral or costandard elements in the lattice $\mathbb{MON}$ of all monoid varieties. Further, we prove that an arbitrary upper-modular element of $\mathbb{MON}$ except the variety of all monoids is either a completely regular ...
Gusev, S. V.
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An introduction of F‐graphs, a graph‐theoretic representation of natural numbers
International Journal of Mathematics and Mathematical Sciences, Volume 15, Issue 2, Page 313-317, 1992., 1990 A special type of family graphs (F‐graphs, for brevity) are introduced. These are cactus‐type graphs which form infinite families under an attachment operation. Some of the characterizing properties of F‐graphs are discussed. Also, it is shown that, together with the attachment operation, these families form an infinite, commutative semigroup with unit
E. J. Farrell
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On some varieties of ai-semirings satisfying xp+1 ≈ x
Open Mathematics, 2018 The aim of this paper is to study the lattice of subvarieties of the ai-semiring variety defined by the additional ...
Wang Aifa, Shao Yong
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The semaphore codes attached to a Turing machine via resets and their various limits [PDF]
, 2016 We introduce semaphore codes associated to a Turing machine via resets. Semaphore codes provide an approximation theory for resets. In this paper we generalize the set-up of our previous paper "Random walks on semaphore codes and delay de Bruijn ...
Rhodes, John +2 more
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Completely Archimedean Semirings
Discussiones Mathematicae - General Algebra and Applications, 2018 In this paper we give a structural description of completely Archimedean semirings which is an extension of the structure theorem of completely Archimedean semigroups.
Maity Sunil K., Chatterjee Rumpa
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