A Laradji, A Umar - Semigroup Forum, 2004 - Springer
Abstract Let D_n (\calO_n) be the semigroup of all finite order-decreasing (order-preserving) full transformations of an n-element chain, and let D(n,r)={α∈D_n:|Imα|≦r\} …
L Cossu, S Tringali - Israel Journal of Mathematics, 2024 - Springer
Let⪯ be a preorder on a monoid H with identity 1 H and s be an integer≥ 2. The⪯-height of an element x∈ H is the supremum of the integers k≥ 1 for which there is a (strictly)⪯ …
A Umar - Algebra and discrete mathematics, 2014 - irbis-nbuv.gov.ua
Let Xn={1, 2,..., n}. On a partial transformation α: Dom α⊆ Xn→ Im α⊆ Xn of Xn the following parameters are defined: the breadth or width of α is| Dom α|, the collapse of α is c (α)=|∪ t∈ …
DB Li, WT Zhang, YF Luo - Journal of Algebra and Its Applications, 2022 - World Scientific
Let 𝒪 𝒫 ℰ n be the monoid of all orientation-preserving and extensive full transformations on {1, 2,…, n} ordered in the standard way. In this paper, we determine the minimum generating …
Y Kemprasit, T Changphas - Bulletin of the Australian Mathematical …, 2000 - cambridge.org
The semigroup OT (X) of all order-preserving total transformations of a finite chain X is known to be regular. We extend this result to subchains of Z; and we characterise when OT …
PM Catarino - Semigroups and Applications, 1998 - World Scientific
In 1962 Alzenstat [1] found a presentation for the monoid On of all order-preserving full transformations of a finite chain. In this work we find a presentation for the monoid OPn …
P Zhao, H Hu - Journal of Algebra and Its Applications, 2025 - World Scientific
Let 𝒪 𝒫 ℰ n be the monoid of all orientation-preserving and extensive full transformations on {1,…, n}. In this paper, we compute the rank and the idempotent rank of the ideals of the …
DB Li, WT Zhang, YF Luo - Semigroup Forum, 2022 - Springer
For n∈ N, let OPE n, k be the monoid of all orientation-preserving k-extensive full transformations on {1,…, n} ordered in the standard way. In this paper, it is shown that OPE …