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Weakly separative weakly commutative semigroups
Semigroup Forum, 2014zbMATH Open Web Interface contents unavailable due to conflicting licenses.
A. Nagy
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Commutative Non-Singular Semigroups
Canadian Mathematical Bulletin, 1977It is well known (see [5]) that the maximal right quotient ring of a ringRis (von Neumann) regular if and only ifRis (right) non-singular (every large right ideal is dense). In [8] it was shown that for a semigroupS, the regularity ofQ(S), the maximal right quotient semigroup [7], is independent of the non-singularity ofS.
Johnson, C. S. jun., McMorris, F. R.
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Galois theories of commutative semigroups via semilattices
Theory and Applications of Categories, 2013The classes of stably-vertical, normal, separable, inseparable, purely in- separable and covering morphisms, dened in categorical Galois theory, are characterized for the reection of the variety of commutative semigroups into its subvariety of semi ...
Isabel A. Xarez, J. Xarez
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2001
In this chapter we deal with semigroups in which the Green equivalence R (L, H) is a congruence. These semigroups are called R-commutative (L-commutative, H-commutative) semigroups. It is clear that a semigroup is H-commutative if and only if it is RR-commutative and L-commutative.
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In this chapter we deal with semigroups in which the Green equivalence R (L, H) is a congruence. These semigroups are called R-commutative (L-commutative, H-commutative) semigroups. It is clear that a semigroup is H-commutative if and only if it is RR-commutative and L-commutative.
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2001
A semigroup S is called left (right) weakly commutative if, for every a, b ∈ S, there exist x ∈ S and a positive integer n such that (ab) n = bx ((ab) n = xa). A semigroup which is both left and right weakly commutative is called a weakly commutative semigroup.
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A semigroup S is called left (right) weakly commutative if, for every a, b ∈ S, there exist x ∈ S and a positive integer n such that (ab) n = bx ((ab) n = xa). A semigroup which is both left and right weakly commutative is called a weakly commutative semigroup.
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FINITELY GENERATED COMMUTATIVE ARCHIMEDEAN SEMIGROUPS
Acta Mathematica Scientia, 2003Let \(S\) be an additive, commutative semigroup. Then \(S\) is said to be an Archimedean (resp., \(MJ\)-) semigroup if for all \(x,y\in S\), there is a \(z\in S\) and an integer \(k\geq 1\) such that \(kx=y+z\) (resp., there are integers \(m,n\geq 1\) such that \(mx=ny\)), and \(S\) is an \(\mathcal N\)-semigroup if \(S\) is a cancellative, Archimedean
Rosales, J. C., García-García, J. I.
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On the spectra of commutative semigroups
Semigroup Forum, 2020Huanrong Wu, Qingguo Li
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2001
A semigroup S is called left (right) quasi commutative if, for every a, b Δ S, there is a positive integer r such that ab = b r a (ab = ba r ). A semigroup S is called σ-reflexive if ab Δ H implies ba Δ H for every a, b Δ S and every subsemigroup H of S.
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A semigroup S is called left (right) quasi commutative if, for every a, b Δ S, there is a positive integer r such that ab = b r a (ab = ba r ). A semigroup S is called σ-reflexive if ab Δ H implies ba Δ H for every a, b Δ S and every subsemigroup H of S.
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Externally commutative semigroups
2001In this chapter we deal with semigroups satisfying the identity axb = bxa. These semigroups are called externally commutative semigroups. It is clear that an externally commutative semigroup is medial. Thus the externally commutative semigroups are semilattice of externally commutative archimedean semigroups. A semigroup is externally commutative and 0-
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