Structure

category of partially ordered sets without isolated points

Notation Posnoiso\Pos_{\noiso} Objects partially ordered sets that have no isolated points Morphisms order-preserving functions Related Pos\Pos
Here, a point is called isolated if it is not comparable to any other point. Thus, we consider partially ordered sets whose connected components have cardinality ≥2\geq 2. This category provides an example of an infinitary extensive category that is not Cauchy complete.

Satisfied properties

Assigned properties

Deduced properties

Unsatisfied properties

Assigned properties

Deduced properties*

*This also uses the deduced satisfied properties.

Unknown properties

—

Special objects

  • initial object: empty poset
  • products: [non-empty case] direct products with the evident partial order
  • coproducts: disjoint union with the obvious partial order in which distinct summands are incomparable

Special morphisms

  • isomorphisms: bijective functions that are order-preserving and order-reflecting
  • monomorphisms: injective order-preserving functions
  • epimorphisms: surjective order-preserving functions
  • regular monomorphisms: embeddings
  • regular epimorphisms: