Let $\webleft (X,\preceq _{X}\webright )$ be a poset and let $\mathcal{C}$ be a category.

  1. Functoriality. The assignment $\webleft (X,\preceq _{X}\webright )\mapsto X_{\mathsf{pos}}$ defines a functor
    \[ \webleft (-\webright )_{\mathsf{pos}}\colon \mathsf{Pos}\to \mathsf{Cats}. \]
  2. Fully Faithfulness. The functor $\webleft (-\webright )_{\mathsf{pos}}$ of Item 1 is fully faithful.
  3. Characterisations. The following conditions are equivalent:
    1. The category $\mathcal{C}$ is posetal.
    2. For each $A,B\in \text{Obj}\webleft (\mathcal{C}\webright )$ and each $f,g\in \textup{Hom}_{\mathcal{C}}\webleft (A,B\webright )$, we have $f=g$.

Item 1: Functoriality
Omitted.
Item 2: Fully Faithfulness
Omitted.

Item 3: Characterisations
Clear.


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