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 2013Show all

3 papers · 1 filter

math.CO2013★ 1 cited

Lattice Paths and Order-preserving Partial Transformations

A. Laradji, A. Umar

Let $P O_{n}$ be the semigroup of all order-preserving partial transformations of a finite chain. It is shown that there exist bijections between the set of certain lattice pat…

math.GR2013★ 2 cited

A countable family of finitely presented infinite congruence-free monoids

Alan J. Cain, Victor Maltcev, Abdullahi Umar

We prove that monoids $Mon ⟨ a, b, c, d : a^{n} b = 0, a c = 1, d b = 1, d c = 1, d ab = 1, d a^{2} b = 1, \dots, d a^{n - 1} b = 1 ⟩$ are congruence-free for all $n \geq 1$ . This provides a ne…

math.CO2013

Constructing Even Order Magic Squares By Consecutive Numbering

A. M. Ibrahim, H. M. Jibril, A. Umar

The aim of this note is to introduce fastest new general methods for the construction of double and single even order magic squares. As in [5], the method for double even order mag…