# Commutativity theorems for cancellative semigroups

## Related Articles

- Levi's Commutator Theorems for Cancellative Semigroups. Padmanabhan, R.; McCune, W.; Veroff, R.; Schein, Boris M. // Semigroup Forum;Jul/Aug2005, Vol. 71 Issue 1, p152
A conjecture of Padmanabhan, on provability in cancellative semigroups, is addressed. Several of Levi's group theory commutator theorems are proved for cancellative semigroups. The proofs, found by automated deduction, support the conjecture.

- Absolute graphs with prescribed endomorphism monoid. Droste, Manfred; Göbel, Rüdiger; Pokutta, Sebastian // Semigroup Forum;Mar/Apr2008, Vol. 76 Issue 2, p256
We consider endomorphism monoids of graphs. It is well-known that any monoid can be represented as the endomorphism monoid M of some graph Î“ with countably many colors. We give a new proof of this theorem such that the isomorphism between the endomorphism monoid $\mathop{\rm End}\nolimits...

- Some Constructions Related to Rees Matrix Semigroups. Petrich, Mario // Semigroup Forum;1999, Vol. 59 Issue 2, p244
For the translational hulls of two Rees matrix semigroups represented by means of matrices, we construct all their isomorphisms again in matrix form. These are matrices of arbitrary size over a group with zero satisfying certain conditions on nonzero entries. We introduce the concept of a...

- A construction of weakly inverse semigroups. Bing Jun Yu; Yan Li // Acta Mathematica Sinica;May2009, Vol. 25 Issue 5, p759
Let So be an inverse semigroup with semilattice biordered set Eo of idempotents and E a weakly inverse biordered set with a subsemilattice E P = { e âˆˆ E | âˆ€ f âˆˆ E, S( f, e) âŠ† Ï‰( e)} isomorphic to Eo by Î¸: E P â†’ Eo. In this paper, it is proved that if âˆ€...

- On the Characterization of Topological Semigroups on Closed Intervals. Ricci, Roberto Ghiselli // Semigroup Forum;May/Jun2006, Vol. 72 Issue 3, p419
Topological linearly ordered semigroups defined on connected and compact sets are studied. Particularly, two representation theorems for the o-embedding of such semigroups into the real numbers with standard operations are provided, weakening the crucial assumption of cancellativity. A...

- Flatness and Coproducts. Golchin, Akbar // Semigroup Forum;May/Jun2006, Vol. 72 Issue 3, p433
In this paper by a new proof we will show that most of flatness properties of acts over monoids can be transferred to their coproduct and vice versa.

- Regular Semigroups with Inverse Transversals. Fenglin Zhu; M�rki, L. // Semigroup Forum;Sep/Oct2006, Vol. 73 Issue 2, p207
Let C be a semiband with an inverse transversal $C^{\circ}$ . In [7], G.T. Song and F.L. Zhu construct a fundamental regular semigroup $T_{C,C^{\circ}}$ with an inverse transversal $T_{C,C^{\circ}}^{\circ}$ . $T_{C,C^{\circ}}$ is isomorphic to a subsemigroup of the Hall semigroup of C but it is...

- The Smallest Regular Semigroups with all Four Skew Pairs of Idempotents. Blyth, T. S.; Santos, M. H. Almeida // Semigroup Forum;Sep/Oct2004, Vol. 69 Issue 2, p230
An ordered pair (e, f) of idempotents of a regular semigroup is called a skew pair if ef is not idempotent whereas fe is idempotent.We have shown previously [1] that there are four distinct types of skew pairs of idempotents. Here we consider the smallest regular semigroups that contain...

- The Isomorphism Problem for Type-W Semigroups. Pengge Zhang; Sanyang Liu // Southeast Asian Bulletin of Mathematics;2006, Vol. 30 Issue 2, p383
The purpose of this paper is to consider the isomorphic problem for type-W semigroups. Necessary and sufficient conditions when type-W semigroups are isomorphic will be given. In this paper, we generalize results of T.E. Hall in 1989 [9].

- On Lattice Isomorphisms of Inverse Semigroups, II. Jones, Peter R.; Pastijn, Francis J. // Semigroup Forum;Nov2006, Vol. 73 Issue 3, p330
A lattice isomorphism between inverse semigroups S and T is an isomorphism between their lattices of inverse subsemigroups. When S is combinatorial, it has long been known that a bijection is induced between S and T. Various authors have introduced successively weaker "archimedean" hypotheses...