CatDat

category of free abelian groups

This is the full subcategory of Ab\Ab that consists of the free abelian groups.

Satisfied Properties

Assigned properties

Deduced properties

Unsatisfied Properties

Assigned properties

Deduced properties*

*This also uses the deduced satisfied properties.

Unknown properties

There are 4 properties for which the database doesn't have an answer if they are satisfied or not. Please help to contribute the data!

Undecidable properties

There is 1 property for which it cannot be decided if it is satisfied or not.

Special objects

  • terminal object: trivial group
  • initial object: trivial group
  • products: [finite case] direct sums
  • coproducts: direct sums

Special morphisms

  • isomorphisms: bijective homomorphisms
  • monomorphisms: injective homomorphisms
  • epimorphisms: homomorphisms f:ABf : A \to B with the property that f(A)f(A) is not contained in a proper direct summand of BB
  • regular monomorphisms: injective homomorphisms f:ABf : A \to B with the property that B/f(A)B/f(A) is free abelian (which are automatically split monomorphisms)
  • regular epimorphisms: surjective homomorphisms (which are automatically split epimorphisms)

Morphisms

The database stores 1 morphism based on the category of free abelian groups.