A. Umar

activity

20102022

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

2 citations · 4 across the 10 of their papers we have counts for

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3 papers · 1 filter

math.CO2022

Combinatorial results for order-preserving partial injective contraction mappings

Bayo Musa Ahmed, Nadia Aldhamri, Fatma Al-Kharousi +2

Let $I_{n}$ be the symmetric inverse semigroup on $X_{n} = {1, 2, \dots, n}$ . Let $O C I_{n}$ be the subsemigroup of $I_{n}$ consisting of all order-preser…

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.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…