5 papers
Subsemigroup, ideal and congruence growth of free semigroups
Alex Bailey, Martin Finn-Sell, Robert Snocken
Using Rees index, the subsemigroup growth of free semigroups is investigated. Lower and upper bounds for the sequence are given and it is shown to have superexponential growth of s…
A short note on strongly flat covers of acts over monoids
Alex Bailey, James Renshaw
Recently two different concepts of covers of acts over monoids have been studied. That based on coessential epimorphisms and that based on Enochs' definition of a flat cover of a m…
Weak Factorization Systems for S-acts
Alex Bailey, James Renshaw
The concept of a weak factorization system has been studied extensively in homotopy theory and has recently found an application in one of the proofs of the celebrated flat cover c…
Covers of acts over monoids II
Alex bailey, James Renshaw
In 1981 Edgar Enochs conjectured that every module has a flat cover and finally proved this in 2001. Since then a great deal of effort has been spent on studying different types of…
Covers of acts over monoids and pure epimorphisms
Alex Bailey, James Renshaw
In 2001 Enoch's celebrated flat cover conjecture was finally proven and the proofs (two different proofs were presented in the same paper [4]) have since generated a great deal of…