We formulate an alternative approach to describing Ehresmann semigroups by means of left and right étale actions of a meet semilattice on a category. We also characterize the Ehresmann semigroups that arise as the set of all subsets of a finite category. As applications, we prove that every restriction semigroup can be nicely embedded into a restriction semigroup constructed from a category, and we describe when a restriction semigroup can be nicely embedded into an inverse semigroup.
|Number of pages||13|
|Early online date||4 Jun 2021|
|Publication status||Published - Dec 2021|
- Ehresmann semigroups
- Finite Boolean algebras
ASJC Scopus subject areas
- Algebra and Number Theory