On Ehresmann semigroups

Mark V. Lawson*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)
21 Downloads (Pure)


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.

Original languageEnglish
Pages (from-to)953-965
Number of pages13
JournalSemigroup Forum
Issue number3
Early online date4 Jun 2021
Publication statusPublished - Dec 2021


  • Categories
  • Ehresmann semigroups
  • Finite Boolean algebras

ASJC Scopus subject areas

  • Algebra and Number Theory


Dive into the research topics of 'On Ehresmann semigroups'. Together they form a unique fingerprint.

Cite this