CatDat

category of finite sets and surjections

This category is badly-behaved in itself, but it appears in representation theory. It has two connected components, consisting of the empty set and the non-empty finite sets.

Satisfied Properties

Properties from the database

Deduced properties

Unsatisfied Properties

Properties from the database

Deduced properties*

*This also uses the deduced satisfied properties.

Unknown properties

Special objects

Special morphisms

  • isomorphisms: bijective maps
  • monomorphisms: bijective maps
  • epimorphisms: every morphism
  • regular monomorphisms: same as monomorphisms
  • regular epimorphisms: same as epimorphisms