Category of preorders #
THIS FILE IS SYNCHRONIZED WITH MATHLIB4. Any changes to this file require a corresponding PR to mathlib4.
This defines Preord
, the category of preorders with monotone maps.
The category of preorders.
Equations
@[protected, instance]
Equations
- Preord.order_hom.category_theory.bundled_hom = {to_fun := order_hom.to_fun, id := order_hom.id, comp := order_hom.comp, hom_ext := order_hom.ext, id_to_fun := Preord.order_hom.category_theory.bundled_hom._proof_1, comp_to_fun := Preord.order_hom.category_theory.bundled_hom._proof_2}
@[protected, instance]
@[protected, instance]
@[protected, instance]
Equations
Constructs an equivalence between preorders from an order isomorphism between them.
Equations
- Preord.iso.mk e = {hom := ↑e, inv := ↑(e.symm), hom_inv_id' := _, inv_hom_id' := _}
order_dual
as a functor.
@[simp]
The equivalence between Preord
and itself induced by order_dual
both ways.
Equations
- Preord.dual_equiv = category_theory.equivalence.mk Preord.dual Preord.dual (category_theory.nat_iso.of_components (λ (X : Preord), Preord.iso.mk (order_iso.dual_dual ↥X)) Preord.dual_equiv._proof_1) (category_theory.nat_iso.of_components (λ (X : Preord), Preord.iso.mk (order_iso.dual_dual ↥X)) Preord.dual_equiv._proof_2)
@[simp]
@[simp]
@[protected, instance]
@[protected, instance]
Equations
- Preord_to_Cat.category_theory.full = {preimage := λ (X Y : Preord) (f : Preord_to_Cat.obj X ⟶ Preord_to_Cat.obj Y), {to_fun := f.obj, monotone' := _}, witness' := Preord_to_Cat.category_theory.full._proof_2}