Results 1 to 10 of about 1,243,990 (68)
Biordered sets come from semigroups [PDF]
The biordered set of a semigroup is the set of idempotents of the semigroup together with the partial operation obtained by restriction of the multiplication to those pairs of idempotents whose product is equal to one of them (i.e. one is a one-sided zero of the other).
Easdown, D
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PERIODIC ELEMENTS OF THE FREE IDEMPOTENT GENERATED SEMIGROUP ON A BIORDERED SET [PDF]
We show that every periodic element of the free idempotent generated semigroup on an arbitrary biordered set belongs to a subgroup of the semigroup.
David Easdown +2 more
openaire +8 more sources
\textit{K. S. S. Nambooripad} [Mem. Am. Math. Soc. 224 (1979; Zbl 0457.20051)] introduced the concept of a (regular) biordered set to abstractly characterize the set of idempotents of a regular semigroup. He also described the biordered sets associated with bands.
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Reconstructing some idempotent-generated semigroups from their biordered sets
The authors investigate how many informations on a semigroup \(S\) are given by the partial algebra \(E(S)\) of the idempotents of \(S\) where a product of \((e,f)\) is defined iff, under the multiplication of \(S\), \(ef\) or \(fe\) is equal to one of its factors. \(E(S)\) is the biordered set of \(S\).
T E Hall
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A concept of variety for regular biordered sets
A regular biordered set \((E,\cdot,\omega^ l, \omega^ r)\) is a set \(E\) together with two quasiorders \(\omega^ l\) and \(\omega^ r\) and a partial binary operation \(\cdot\), satisfying a finite (but somehow complicated) system of axioms. Regular biordered sets were introduced by \textit{K. S. S. Nambooripad} [Mem. Am. Math. Soc. 224 (1979; Zbl 0457.
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Independence of axioms for biordered sets
Biordered sets were introduced by \textit{K. S. S. Nambooripad} as an abstraction of the partial semigroup of idempotents of a semigroup [Mem. Am. Math. Soc. 224 (1979; Zbl 0457.20051]. Let X, Y be sets, \(\rho \subseteq X\times Y\) and put \(\rho(y)=\{x\in X:\quad x\rho y\}.\) A partial algebra is defined to be a set E equipped with a partial binary ...
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Biordered sets and complemented modular lattices
In this paper we give a structure theorem for the biordered set of a strongly regular Baer semigroup. As a result we shall be able to construct the biordered set of the multiplicative semigroup of a regular ring in terms of the complemented modular lattice which is coordinatized by this regular ring.
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ℓ2$\ell ^2$‐Betti numbers and coherence of random groups
Abstract We study ℓ2$\ell ^2$‐Betti numbers, coherence and (virtual) fibring of random groups in the few‐relator model. In particular, random groups with negative Euler characteristic are coherent, have ℓ2$\ell ^2$‐homology concentrated in dimension 1 and embed in a virtually free‐by‐cyclic group with high probability.
Dawid Kielak +2 more
wiley +1 more source
Relations between cross-connections and biordered sets
K S S Nambooripad
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Biordered sets are biordered subsets of idempotents of semigroups [PDF]
AbstractA new arrow notation is used to describe biordered sets. Biordered sets are characterized as biordered subsets of the partial algebras formed by the idempotents of semigroups. Thus it can be shown that in the free semigroup on a biordered set factored out by the equations of the biordered set there is no collapse of idempotents and no new ...
openaire +2 more sources

