Structure

simplex category

Notation Δ\Delta Objects the non-empty ordered sets [n]≔{0<⋯<n}[n] \coloneqq \{0 < \cdots < n\} for n∈Nn \in \IN Morphisms order-preserving maps Related FinOrd\FinOrd, Set≠∅\Setne, sSet\sSet, Δ≤1\Delta^{\leq 1} External nLab link
The simplex category is a skeleton of FinOrd∖{∅}\FinOrd \setminus \{\varnothing\}. It plays an important role in topology and is used to define the category of simplicial sets.

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

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Special morphisms

  • isomorphisms: bijective order-preserving maps
  • monomorphisms: injective order-preserving maps
  • epimorphisms: surjective order-preserving maps
  • regular monomorphisms: same as monomorphisms
  • regular epimorphisms: same as epimorphisms