Structure

category of partially ordered sets

Notation Pos\Pos Objects partially ordered sets (aka posets), i.e. sets equipped with a reflexive, transitive, and antisymmetric relation Morphisms order-preserving functions Related PreOrd\PreOrd, FinOrd\FinOrd, Posnoiso\Pos_{\noiso}, Bin\Bin External nLab link
Despite the many similarities with PreOrd\PreOrd, the main difference is that the forgetful functor Pos→Set\Pos \to \Set has no right adjoint. It is a full subcategory of Bin\Bin.

Satisfied properties

Assigned properties

Deduced properties

Unsatisfied properties

Assigned properties

Deduced properties*

*This also uses the deduced satisfied properties.

Unknown properties

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Special objects

  • terminal object: singleton poset
  • initial object: empty poset
  • products: direct products with the evident partial order
  • coproducts: disjoint union with the obvious partial order in which distinct summands are incomparable

Special morphisms