CatDat

proset of integers w.r.t. divisibility

  • notation: (Z,)(\IZ,\mid)
  • objects: integers
  • morphisms: a unique morphism (a,b):ab(a,b) : a \to b if aa divides bb
  • Related categories: (N,)(\IN,\leq)

This is a proset, not a poset, because aa and a-a divide each other, but are not equal for a0a \neq 0. Notice that this category is equivalent (but not isomorphic) to (N,)(\IN,\mid).

Satisfied Properties

Assigned properties

Deduced properties

Unsatisfied Properties

Assigned properties

Deduced properties*

*This also uses the deduced satisfied properties.

Unknown properties

Special objects

  • terminal object: 00
  • initial object: 11
  • products: greatest common divisor
  • coproducts: the least common multiple, can be 00 for infinite families

Special morphisms

  • isomorphisms: the identities (a,a):aa(a,a) : a \to a and the isomorphisms (a,a):aa(a,-a) : a \to -a for aZa \in \IZ
  • monomorphisms: every morphism
  • epimorphisms: every morphism
  • regular monomorphisms: same as isomorphisms
  • regular epimorphisms: same as isomorphisms