A. Umar

activity

20102024

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

2 citations · 4 across the 11 of their papers we have counts for

collaborators

Showing 2018Show all

3 papers · 1 filter

math.GR2018

On certain semigroups of full contractions of a finite chain

A. Umar, M. M. Zubairu

Let $[n] = {1, 2, \dots, n}$ be a finite chain and let $T_{n}$ be the semigroup of full transformations on $[n]$ . Let $\mathcal{CT}_{n}=\{α\in \mathcal{T}_{n}: (for ~all~x,…

math.GR2018

On certain semigroups of partial contractions of a finite chain

A. Umar, M. M. Zubairu

Let $[n] = {1, 2, \dots, n}$ be a finite chain and let $P_{n}$ be the semigroup of partial transformations on $[n]$ . Let $\mathcal{CP}_{n}=\{α\in \mathcal{P}_{n}: (for ~all…

math.GR2018

Regularity and Green's relations for the semigroup of partial contractions of a finite chain

B. Ali, A. Umar, M. M. Zubairu

Let $[n] = {1, 2, \dots, n}$ be a finite chain and let $P_{n}$ be the semigroup of partial transformations on $[n]$ . Let $\mathcal{CP}_{n}=\{α\in \mathcal{P}_{n}: (for~all…