The category of quivers #
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The category of (bundled) quivers, and the free/forgetful adjunction between Cat
and Quiv
.
@[nolint]
Category of quivers.
Equations
Instances for category_theory.Quiv
@[protected, instance]
Equations
@[protected, instance]
Construct a bundled Quiv
from the underlying type and the typeclass.
Equations
@[protected, instance]
@[protected, instance]
Category structure on Quiv
Equations
- category_theory.Quiv.category = {to_category_struct := {to_quiver := {hom := λ (C D : category_theory.Quiv), ↥C ⥤q ↥D}, id := λ (C : category_theory.Quiv), 𝟭q ↥C, comp := λ (C D E : category_theory.Quiv) (F : C ⟶ D) (G : D ⟶ E), F ⋙q G}, id_comp' := category_theory.Quiv.category._proof_1, comp_id' := category_theory.Quiv.category._proof_2, assoc' := category_theory.Quiv.category._proof_3}
@[simp]
@[simp]
The forgetful functor from categories to quivers.
Equations
- category_theory.Quiv.forget = {obj := λ (C : category_theory.Cat), category_theory.Quiv.of ↥C, map := λ (C D : category_theory.Cat) (F : C ⟶ D), category_theory.functor.to_prefunctor F, map_id' := category_theory.Quiv.forget._proof_1, map_comp' := category_theory.Quiv.forget._proof_2}
@[simp]
theorem
category_theory.Cat.free_map_map
(V W : category_theory.Quiv)
(F : V ⟶ W)
(X Y : ↥(category_theory.Cat.of (category_theory.paths ↥V)))
(f : X ⟶ Y) :
(category_theory.Cat.free.map F).map f = prefunctor.map_path F f
@[simp]
@[simp]
theorem
category_theory.Cat.free_map_obj
(V W : category_theory.Quiv)
(F : V ⟶ W)
(X : ↥(category_theory.Cat.of (category_theory.paths ↥V))) :
(category_theory.Cat.free.map F).obj X = F.obj X
The functor sending each quiver to its path category.
Equations
- category_theory.Cat.free = {obj := λ (V : category_theory.Quiv), category_theory.Cat.of (category_theory.paths ↥V), map := λ (V W : category_theory.Quiv) (F : V ⟶ W), {obj := λ (X : ↥(category_theory.Cat.of (category_theory.paths ↥V))), F.obj X, map := λ (X Y : ↥(category_theory.Cat.of (category_theory.paths ↥V))) (f : X ⟶ Y), prefunctor.map_path F f, map_id' := _, map_comp' := _}, map_id' := category_theory.Cat.free._proof_3, map_comp' := category_theory.Cat.free._proof_4}
def
category_theory.Quiv.lift
{V : Type u}
[quiver V]
{C : Type u_1}
[category_theory.category C]
(F : V ⥤q C) :
Any prefunctor into a category lifts to a functor from the path category.
Equations
- category_theory.Quiv.lift F = {obj := λ (X : category_theory.paths V), F.obj X, map := λ (X Y : category_theory.paths V) (f : X ⟶ Y), category_theory.compose_path (F.map_path f), map_id' := _, map_comp' := _}
@[simp]
theorem
category_theory.Quiv.lift_map
{V : Type u}
[quiver V]
{C : Type u_1}
[category_theory.category C]
(F : V ⥤q C)
(X Y : category_theory.paths V)
(f : X ⟶ Y) :
@[simp]
theorem
category_theory.Quiv.lift_obj
{V : Type u}
[quiver V]
{C : Type u_1}
[category_theory.category C]
(F : V ⥤q C)
(X : category_theory.paths V) :
(category_theory.Quiv.lift F).obj X = F.obj X
The adjunction between forming the free category on a quiver, and forgetting a category to a quiver.
Equations
- category_theory.Quiv.adj = category_theory.adjunction.mk_of_hom_equiv {hom_equiv := λ (V : category_theory.Quiv) (C : category_theory.Cat), {to_fun := λ (F : category_theory.Cat.free.obj V ⟶ C), category_theory.paths.of ⋙q category_theory.functor.to_prefunctor F, inv_fun := λ (F : V ⟶ category_theory.Quiv.forget.obj C), category_theory.Quiv.lift F, left_inv := _, right_inv := _}, hom_equiv_naturality_left_symm' := category_theory.Quiv.adj._proof_3, hom_equiv_naturality_right' := category_theory.Quiv.adj._proof_4}