A. Umar

activity

20102025

most citedA countable family of finitely presented infinite congruence-free monoids

2 citations · 4 across the 14 of their papers we have counts for

collaborators

Showing 2022 · math.GRShow all

2 papers · 2 filters

math.GR2022

On the combinatorial and rank properties of certain subsemigroups of full contractions of a finite chain

Muhammad Mansur Zubairu, Abdullahi Umar, Muhammad Jada Aliyu

Let $[n] = {1, 2, \dots, n}$ be a finite chain and let $C T_{n}$ be the semigroup of full contractions on $[n]$ . Denote $O R C T_{n}$ and $O C T_{n}$ to be th…

math.GR2022★ 1 cited

On certain Semigroup of Order-decreasing Full Contraction Mappings of a Finite Chain

M. M. Zubairu, A. Umar, J. A. Aliyu

Let $C T_{n}$ be the semigroup of full contraction mappings on $[n] = {1, 2, \dots, n}$ , and let $O C T_{n}$ and $O D C T_{n}$ be the subsemigroups consisting of al…