PROPER COVERS OF AMPLE MONOIDS
John Fountain, Gracinda M. S. Gomes · Proceedings of the Edinburgh Mathematical Society · 2006
Abstract Proper ample monoids are described by means of a certain category acted upon on both sides by a cancellative monoid. Making use of this characterization, we show that every ample monoid $S$ has a proper ample cover, which can be taken to be finite whenever $S$ is finite.