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forget_enrichment.of (X : C) : forget_enrichment W C
X
def
category_theory.forget_enrichment.of
category_theory.enriched
src/category_theory/enriched/basic.lean
[ "category_theory.monoidal.types.symmetric", "category_theory.monoidal.types.coyoneda", "category_theory.monoidal.center", "tactic.apply_fun" ]
[]
Typecheck an object of `C` as an object of `forget_enrichment W C`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
forget_enrichment.to (X : forget_enrichment W C) : C
X
def
category_theory.forget_enrichment.to
category_theory.enriched
src/category_theory/enriched/basic.lean
[ "category_theory.monoidal.types.symmetric", "category_theory.monoidal.types.coyoneda", "category_theory.monoidal.center", "tactic.apply_fun" ]
[]
Typecheck an object of `forget_enrichment W C` as an object of `C`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
forget_enrichment.to_of (X : C) : forget_enrichment.to W (forget_enrichment.of W X) = X
rfl
lemma
category_theory.forget_enrichment.to_of
category_theory.enriched
src/category_theory/enriched/basic.lean
[ "category_theory.monoidal.types.symmetric", "category_theory.monoidal.types.coyoneda", "category_theory.monoidal.center", "tactic.apply_fun" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
forget_enrichment.of_to (X : forget_enrichment W C) : forget_enrichment.of W (forget_enrichment.to W X) = X
rfl
lemma
category_theory.forget_enrichment.of_to
category_theory.enriched
src/category_theory/enriched/basic.lean
[ "category_theory.monoidal.types.symmetric", "category_theory.monoidal.types.coyoneda", "category_theory.monoidal.center", "tactic.apply_fun" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
category_forget_enrichment : category (forget_enrichment W C)
begin let I : enriched_category (Type v) (transport_enrichment (coyoneda_tensor_unit W) C) := infer_instance, exact enriched_category_Type_equiv_category C I, end
instance
category_theory.category_forget_enrichment
category_theory.enriched
src/category_theory/enriched/basic.lean
[ "category_theory.monoidal.types.symmetric", "category_theory.monoidal.types.coyoneda", "category_theory.monoidal.center", "tactic.apply_fun" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
forget_enrichment.hom_of {X Y : C} (f : (𝟙_ W) ⟶ (X ⟶[W] Y)) : forget_enrichment.of W X ⟶ forget_enrichment.of W Y
f
def
category_theory.forget_enrichment.hom_of
category_theory.enriched
src/category_theory/enriched/basic.lean
[ "category_theory.monoidal.types.symmetric", "category_theory.monoidal.types.coyoneda", "category_theory.monoidal.center", "tactic.apply_fun" ]
[]
Typecheck a `(𝟙_ W)`-shaped `W`-morphism as a morphism in `forget_enrichment W C`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
forget_enrichment.hom_to {X Y : forget_enrichment W C} (f : X ⟶ Y) : (𝟙_ W) ⟶ (forget_enrichment.to W X ⟶[W] forget_enrichment.to W Y)
f
def
category_theory.forget_enrichment.hom_to
category_theory.enriched
src/category_theory/enriched/basic.lean
[ "category_theory.monoidal.types.symmetric", "category_theory.monoidal.types.coyoneda", "category_theory.monoidal.center", "tactic.apply_fun" ]
[]
Typecheck a morphism in `forget_enrichment W C` as a `(𝟙_ W)`-shaped `W`-morphism.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
forget_enrichment.hom_to_hom_of {X Y : C} (f : (𝟙_ W) ⟶ (X ⟶[W] Y)) : forget_enrichment.hom_to W (forget_enrichment.hom_of W f) = f
rfl
lemma
category_theory.forget_enrichment.hom_to_hom_of
category_theory.enriched
src/category_theory/enriched/basic.lean
[ "category_theory.monoidal.types.symmetric", "category_theory.monoidal.types.coyoneda", "category_theory.monoidal.center", "tactic.apply_fun" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
forget_enrichment.hom_of_hom_to {X Y : forget_enrichment W C} (f : X ⟶ Y) : forget_enrichment.hom_of W (forget_enrichment.hom_to W f) = f
rfl
lemma
category_theory.forget_enrichment.hom_of_hom_to
category_theory.enriched
src/category_theory/enriched/basic.lean
[ "category_theory.monoidal.types.symmetric", "category_theory.monoidal.types.coyoneda", "category_theory.monoidal.center", "tactic.apply_fun" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
forget_enrichment_id (X : forget_enrichment W C) : forget_enrichment.hom_to W (𝟙 X) = (e_id W (forget_enrichment.to W X : C))
category.id_comp _
lemma
category_theory.forget_enrichment_id
category_theory.enriched
src/category_theory/enriched/basic.lean
[ "category_theory.monoidal.types.symmetric", "category_theory.monoidal.types.coyoneda", "category_theory.monoidal.center", "tactic.apply_fun" ]
[]
The identity in the "underlying" category of an enriched category.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
forget_enrichment_id' (X : C) : forget_enrichment.hom_of W (e_id W X) = (𝟙 (forget_enrichment.of W X : C))
(forget_enrichment_id W (forget_enrichment.of W X)).symm
lemma
category_theory.forget_enrichment_id'
category_theory.enriched
src/category_theory/enriched/basic.lean
[ "category_theory.monoidal.types.symmetric", "category_theory.monoidal.types.coyoneda", "category_theory.monoidal.center", "tactic.apply_fun" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
forget_enrichment_comp {X Y Z : forget_enrichment W C} (f : X ⟶ Y) (g : Y ⟶ Z) : forget_enrichment.hom_to W (f ≫ g) = (((λ_ (𝟙_ W)).inv ≫ (forget_enrichment.hom_to W f ⊗ forget_enrichment.hom_to W g)) ≫ e_comp W _ _ _)
rfl
lemma
category_theory.forget_enrichment_comp
category_theory.enriched
src/category_theory/enriched/basic.lean
[ "category_theory.monoidal.types.symmetric", "category_theory.monoidal.types.coyoneda", "category_theory.monoidal.center", "tactic.apply_fun" ]
[]
Composition in the "underlying" category of an enriched category.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
enriched_functor (C : Type u₁) [enriched_category V C] (D : Type u₂) [enriched_category V D]
(obj : C → D) (map : Π X Y : C, (X ⟶[V] Y) ⟶ (obj X ⟶[V] obj Y)) (map_id' : ∀ X : C, e_id V X ≫ map X X = e_id V (obj X) . obviously) (map_comp' : ∀ X Y Z : C, e_comp V X Y Z ≫ map X Z = (map X Y ⊗ map Y Z) ≫ e_comp V (obj X) (obj Y) (obj Z) . obviously)
structure
category_theory.enriched_functor
category_theory.enriched
src/category_theory/enriched/basic.lean
[ "category_theory.monoidal.types.symmetric", "category_theory.monoidal.types.coyoneda", "category_theory.monoidal.center", "tactic.apply_fun" ]
[]
A `V`-functor `F` between `V`-enriched categories has a `V`-morphism from `X ⟶[V] Y` to `F.obj X ⟶[V] F.obj Y`, satisfying the usual axioms.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
enriched_functor.id (C : Type u₁) [enriched_category V C] : enriched_functor V C C
{ obj := λ X, X, map := λ X Y, 𝟙 _, }
def
category_theory.enriched_functor.id
category_theory.enriched
src/category_theory/enriched/basic.lean
[ "category_theory.monoidal.types.symmetric", "category_theory.monoidal.types.coyoneda", "category_theory.monoidal.center", "tactic.apply_fun" ]
[]
The identity enriched functor.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
enriched_functor.comp {C : Type u₁} {D : Type u₂} {E : Type u₃} [enriched_category V C] [enriched_category V D] [enriched_category V E] (F : enriched_functor V C D) (G : enriched_functor V D E) : enriched_functor V C E
{ obj := λ X, G.obj (F.obj X), map := λ X Y, F.map _ _ ≫ G.map _ _, }
def
category_theory.enriched_functor.comp
category_theory.enriched
src/category_theory/enriched/basic.lean
[ "category_theory.monoidal.types.symmetric", "category_theory.monoidal.types.coyoneda", "category_theory.monoidal.center", "tactic.apply_fun" ]
[]
Composition of enriched functors.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
enriched_functor.forget {C : Type u₁} {D : Type u₂} [enriched_category W C] [enriched_category W D] (F : enriched_functor W C D) : (forget_enrichment W C) ⥤ (forget_enrichment W D)
{ obj := λ X, forget_enrichment.of W (F.obj (forget_enrichment.to W X)), map := λ X Y f, forget_enrichment.hom_of W (forget_enrichment.hom_to W f ≫ F.map (forget_enrichment.to W X) (forget_enrichment.to W Y)), map_comp' := λ X Y Z f g, begin dsimp, apply_fun forget_enrichment.hom_to W, { simp only [...
def
category_theory.enriched_functor.forget
category_theory.enriched
src/category_theory/enriched/basic.lean
[ "category_theory.monoidal.types.symmetric", "category_theory.monoidal.types.coyoneda", "category_theory.monoidal.center", "tactic.apply_fun" ]
[]
An enriched functor induces an honest functor of the underlying categories, by mapping the `(𝟙_ W)`-shaped morphisms.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
graded_nat_trans (A : center V) (F G : enriched_functor V C D)
(app : Π (X : C), A.1 ⟶ (F.obj X ⟶[V] G.obj X)) (naturality : ∀ (X Y : C), (A.2.β (X ⟶[V] Y)).hom ≫ (F.map X Y ⊗ app Y) ≫ e_comp V _ _ _ = (app X ⊗ G.map X Y) ≫ e_comp V _ _ _)
structure
category_theory.graded_nat_trans
category_theory.enriched
src/category_theory/enriched/basic.lean
[ "category_theory.monoidal.types.symmetric", "category_theory.monoidal.types.coyoneda", "category_theory.monoidal.center", "tactic.apply_fun" ]
[]
The type of `A`-graded natural transformations between `V`-functors `F` and `G`. This is the type of morphisms in `V` from `A` to the `V`-object of natural transformations.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
enriched_nat_trans_yoneda (F G : enriched_functor V C D) : Vᵒᵖ ⥤ (Type (max u₁ w))
{ obj := λ A, graded_nat_trans ((center.of_braided V).obj (unop A)) F G, map := λ A A' f σ, { app := λ X, f.unop ≫ σ.app X, naturality := λ X Y, begin have p := σ.naturality X Y, dsimp at p ⊢, rw [←id_tensor_comp_tensor_id (f.unop ≫ σ.app Y) _, id_tensor_comp, category.assoc, category....
def
category_theory.enriched_nat_trans_yoneda
category_theory.enriched
src/category_theory/enriched/basic.lean
[ "category_theory.monoidal.types.symmetric", "category_theory.monoidal.types.coyoneda", "category_theory.monoidal.center", "tactic.apply_fun" ]
[]
A presheaf isomorphic to the Yoneda embedding of the `V`-object of natural transformations from `F` to `G`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
enriched_functor_Type_equiv_functor {C : Type u₁} [𝒞 : enriched_category (Type v) C] {D : Type u₂} [𝒟 : enriched_category (Type v) D] : enriched_functor (Type v) C D ≃ (C ⥤ D)
{ to_fun := λ F, { obj := λ X, F.obj X, map := λ X Y f, F.map X Y f, map_id' := λ X, congr_fun (F.map_id X) punit.star, map_comp' := λ X Y Z f g, congr_fun (F.map_comp X Y Z) ⟨f, g⟩, }, inv_fun := λ F, { obj := λ X, F.obj X, map := λ X Y f, F.map f, map_id' := λ X, by { ext ⟨⟩, exact F.map_id ...
def
category_theory.enriched_functor_Type_equiv_functor
category_theory.enriched
src/category_theory/enriched/basic.lean
[ "category_theory.monoidal.types.symmetric", "category_theory.monoidal.types.coyoneda", "category_theory.monoidal.center", "tactic.apply_fun" ]
[ "inv_fun" ]
We verify that an enriched functor between `Type v` enriched categories is just the same thing as an honest functor.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
enriched_nat_trans_yoneda_Type_iso_yoneda_nat_trans {C : Type v} [enriched_category (Type v) C] {D : Type v} [enriched_category (Type v) D] (F G : enriched_functor (Type v) C D) : enriched_nat_trans_yoneda F G ≅ yoneda.obj ((enriched_functor_Type_equiv_functor F) ⟶ (enriched_functor_Type_equiv_functor G))
nat_iso.of_components (λ α, { hom := λ σ x, { app := λ X, σ.app X x, naturality' := λ X Y f, congr_fun (σ.naturality X Y) ⟨x, f⟩, }, inv := λ σ, { app := λ X x, (σ x).app X, naturality := λ X Y, by { ext ⟨x, f⟩, exact ((σ x).naturality f), }, }}) (by tidy)
def
category_theory.enriched_nat_trans_yoneda_Type_iso_yoneda_nat_trans
category_theory.enriched
src/category_theory/enriched/basic.lean
[ "category_theory.monoidal.types.symmetric", "category_theory.monoidal.types.coyoneda", "category_theory.monoidal.center", "tactic.apply_fun" ]
[]
We verify that the presheaf representing natural transformations between `Type v`-enriched functors is actually represented by the usual type of natural transformations!
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
functor (C : Type u₁) [category.{v₁} C] (D : Type u₂) [category.{v₂} D] extends prefunctor C D : Type (max v₁ v₂ u₁ u₂)
(map_id' : ∀ (X : C), map (𝟙 X) = 𝟙 (obj X) . obviously) (map_comp' : ∀ {X Y Z : C} (f : X ⟶ Y) (g : Y ⟶ Z), map (f ≫ g) = (map f) ≫ (map g) . obviously)
structure
category_theory.functor
category_theory.functor
src/category_theory/functor/basic.lean
[ "tactic.reassoc_axiom", "category_theory.category.basic" ]
[ "prefunctor" ]
`functor C D` represents a functor between categories `C` and `D`. To apply a functor `F` to an object use `F.obj X`, and to a morphism use `F.map f`. The axiom `map_id` expresses preservation of identities, and `map_comp` expresses functoriality. See <https://stacks.math.columbia.edu/tag/001B>.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
id : C ⥤ C
{ obj := λ X, X, map := λ _ _ f, f }
def
category_theory.functor.id
category_theory.functor
src/category_theory/functor/basic.lean
[ "tactic.reassoc_axiom", "category_theory.category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
id_obj (X : C) : (𝟭 C).obj X = X
rfl
lemma
category_theory.functor.id_obj
category_theory.functor
src/category_theory/functor/basic.lean
[ "tactic.reassoc_axiom", "category_theory.category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
id_map {X Y : C} (f : X ⟶ Y) : (𝟭 C).map f = f
rfl
lemma
category_theory.functor.id_map
category_theory.functor
src/category_theory/functor/basic.lean
[ "tactic.reassoc_axiom", "category_theory.category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp (F : C ⥤ D) (G : D ⥤ E) : C ⥤ E
{ obj := λ X, G.obj (F.obj X), map := λ _ _ f, G.map (F.map f) }
def
category_theory.functor.comp
category_theory.functor
src/category_theory/functor/basic.lean
[ "tactic.reassoc_axiom", "category_theory.category.basic" ]
[]
`F ⋙ G` is the composition of a functor `F` and a functor `G` (`F` first, then `G`).
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_map (F : C ⥤ D) (G : D ⥤ E) {X Y : C} (f : X ⟶ Y) : (F ⋙ G).map f = G.map (F.map f)
rfl
lemma
category_theory.functor.comp_map
category_theory.functor
src/category_theory/functor/basic.lean
[ "tactic.reassoc_axiom", "category_theory.category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_id (F : C ⥤ D) : F ⋙ (𝟭 D) = F
by cases F; refl
lemma
category_theory.functor.comp_id
category_theory.functor
src/category_theory/functor/basic.lean
[ "tactic.reassoc_axiom", "category_theory.category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
id_comp (F : C ⥤ D) : (𝟭 C) ⋙ F = F
by cases F; refl
lemma
category_theory.functor.id_comp
category_theory.functor
src/category_theory/functor/basic.lean
[ "tactic.reassoc_axiom", "category_theory.category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_dite (F : C ⥤ D) {X Y : C} {P : Prop} [decidable P] (f : P → (X ⟶ Y)) (g : ¬P → (X ⟶ Y)) : F.map (if h : P then f h else g h) = if h : P then F.map (f h) else F.map (g h)
by { split_ifs; refl, }
lemma
category_theory.functor.map_dite
category_theory.functor
src/category_theory/functor/basic.lean
[ "tactic.reassoc_axiom", "category_theory.category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_prefunctor_obj (F : C ⥤ D) (X : C) : F.to_prefunctor.obj X = F.obj X
rfl
lemma
category_theory.functor.to_prefunctor_obj
category_theory.functor
src/category_theory/functor/basic.lean
[ "tactic.reassoc_axiom", "category_theory.category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_prefunctor_map (F : C ⥤ D) {X Y : C} (f : X ⟶ Y) : F.to_prefunctor.map f = F.map f
rfl
lemma
category_theory.functor.to_prefunctor_map
category_theory.functor
src/category_theory/functor/basic.lean
[ "tactic.reassoc_axiom", "category_theory.category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_prefunctor_comp (F : C ⥤ D) (G : D ⥤ E) : F.to_prefunctor.comp G.to_prefunctor = (F ⋙ G).to_prefunctor
rfl
lemma
category_theory.functor.to_prefunctor_comp
category_theory.functor
src/category_theory/functor/basic.lean
[ "tactic.reassoc_axiom", "category_theory.category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
functor.category : category.{(max u₁ v₂)} (C ⥤ D)
{ hom := λ F G, nat_trans F G, id := λ F, nat_trans.id F, comp := λ _ _ _ α β, vcomp α β }
instance
category_theory.functor.category
category_theory.functor
src/category_theory/functor/category.lean
[ "category_theory.natural_transformation", "category_theory.isomorphism" ]
[]
`functor.category C D` gives the category structure on functors and natural transformations between categories `C` and `D`. Notice that if `C` and `D` are both small categories at the same universe level, this is another small category at that level. However if `C` and `D` are both large categories at the same univers...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
vcomp_eq_comp (α : F ⟶ G) (β : G ⟶ H) : vcomp α β = α ≫ β
rfl
lemma
category_theory.nat_trans.vcomp_eq_comp
category_theory.functor
src/category_theory/functor/category.lean
[ "category_theory.natural_transformation", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
vcomp_app' (α : F ⟶ G) (β : G ⟶ H) (X : C) : (α ≫ β).app X = (α.app X) ≫ (β.app X)
rfl
lemma
category_theory.nat_trans.vcomp_app'
category_theory.functor
src/category_theory/functor/category.lean
[ "category_theory.natural_transformation", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
congr_app {α β : F ⟶ G} (h : α = β) (X : C) : α.app X = β.app X
by rw h
lemma
category_theory.nat_trans.congr_app
category_theory.functor
src/category_theory/functor/category.lean
[ "category_theory.natural_transformation", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
id_app (F : C ⥤ D) (X : C) : (𝟙 F : F ⟶ F).app X = 𝟙 (F.obj X)
rfl
lemma
category_theory.nat_trans.id_app
category_theory.functor
src/category_theory/functor/category.lean
[ "category_theory.natural_transformation", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_app {F G H : C ⥤ D} (α : F ⟶ G) (β : G ⟶ H) (X : C) : (α ≫ β).app X = α.app X ≫ β.app X
rfl
lemma
category_theory.nat_trans.comp_app
category_theory.functor
src/category_theory/functor/category.lean
[ "category_theory.natural_transformation", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_app_assoc {F G H : C ⥤ D} (α : F ⟶ G) (β : G ⟶ H) (X : C) {X' : D} (f : H.obj X ⟶ X') : (α ≫ β).app X ≫ f = α.app X ≫ β.app X ≫ f
by rw [comp_app, assoc]
lemma
category_theory.nat_trans.comp_app_assoc
category_theory.functor
src/category_theory/functor/category.lean
[ "category_theory.natural_transformation", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
app_naturality {F G : C ⥤ (D ⥤ E)} (T : F ⟶ G) (X : C) {Y Z : D} (f : Y ⟶ Z) : ((F.obj X).map f) ≫ ((T.app X).app Z) = ((T.app X).app Y) ≫ ((G.obj X).map f)
(T.app X).naturality f
lemma
category_theory.nat_trans.app_naturality
category_theory.functor
src/category_theory/functor/category.lean
[ "category_theory.natural_transformation", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
naturality_app {F G : C ⥤ (D ⥤ E)} (T : F ⟶ G) (Z : D) {X Y : C} (f : X ⟶ Y) : ((F.map f).app Z) ≫ ((T.app Y).app Z) = ((T.app X).app Z) ≫ ((G.map f).app Z)
congr_fun (congr_arg app (T.naturality f)) Z
lemma
category_theory.nat_trans.naturality_app
category_theory.functor
src/category_theory/functor/category.lean
[ "category_theory.natural_transformation", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mono_of_mono_app (α : F ⟶ G) [∀ (X : C), mono (α.app X)] : mono α
⟨λ H g h eq, by { ext X, rw [←cancel_mono (α.app X), ←comp_app, eq, comp_app] }⟩
lemma
category_theory.nat_trans.mono_of_mono_app
category_theory.functor
src/category_theory/functor/category.lean
[ "category_theory.natural_transformation", "category_theory.isomorphism" ]
[]
A natural transformation is a monomorphism if each component is.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
epi_of_epi_app (α : F ⟶ G) [∀ (X : C), epi (α.app X)] : epi α
⟨λ H g h eq, by { ext X, rw [←cancel_epi (α.app X), ←comp_app, eq, comp_app] }⟩
lemma
category_theory.nat_trans.epi_of_epi_app
category_theory.functor
src/category_theory/functor/category.lean
[ "category_theory.natural_transformation", "category_theory.isomorphism" ]
[]
A natural transformation is an epimorphism if each component is.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
hcomp {H I : D ⥤ E} (α : F ⟶ G) (β : H ⟶ I) : (F ⋙ H) ⟶ (G ⋙ I)
{ app := λ X : C, (β.app (F.obj X)) ≫ (I.map (α.app X)), naturality' := λ X Y f, begin rw [functor.comp_map, functor.comp_map, ←assoc, naturality, assoc, ←map_comp I, naturality, map_comp, assoc] end }
def
category_theory.nat_trans.hcomp
category_theory.functor
src/category_theory/functor/category.lean
[ "category_theory.natural_transformation", "category_theory.isomorphism" ]
[ "map_comp" ]
`hcomp α β` is the horizontal composition of natural transformations.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
hcomp_id_app {H : D ⥤ E} (α : F ⟶ G) (X : C) : (α ◫ 𝟙 H).app X = H.map (α.app X)
by {dsimp, simp}
lemma
category_theory.nat_trans.hcomp_id_app
category_theory.functor
src/category_theory/functor/category.lean
[ "category_theory.natural_transformation", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
id_hcomp_app {H : E ⥤ C} (α : F ⟶ G) (X : E) : (𝟙 H ◫ α).app X = α.app _
by simp
lemma
category_theory.nat_trans.id_hcomp_app
category_theory.functor
src/category_theory/functor/category.lean
[ "category_theory.natural_transformation", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
exchange {I J K : D ⥤ E} (α : F ⟶ G) (β : G ⟶ H) (γ : I ⟶ J) (δ : J ⟶ K) : (α ≫ β) ◫ (γ ≫ δ) = (α ◫ γ) ≫ (β ◫ δ)
by ext; simp
lemma
category_theory.nat_trans.exchange
category_theory.functor
src/category_theory/functor/category.lean
[ "category_theory.natural_transformation", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
flip (F : C ⥤ (D ⥤ E)) : D ⥤ (C ⥤ E)
{ obj := λ k, { obj := λ j, (F.obj j).obj k, map := λ j j' f, (F.map f).app k, map_id' := λ X, begin rw category_theory.functor.map_id, refl end, map_comp' := λ X Y Z f g, by rw [map_comp, ←comp_app] }, map := λ c c' f, { app := λ j, (F.obj j).map f } }.
def
category_theory.functor.flip
category_theory.functor
src/category_theory/functor/category.lean
[ "category_theory.natural_transformation", "category_theory.isomorphism" ]
[ "map_comp" ]
Flip the arguments of a bifunctor. See also `currying.lean`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_hom_inv_app (F : C ⥤ D ⥤ E) {X Y : C} (e : X ≅ Y) (Z : D) : (F.map e.hom).app Z ≫ (F.map e.inv).app Z = 𝟙 _
by simp [← nat_trans.comp_app, ← functor.map_comp]
lemma
category_theory.map_hom_inv_app
category_theory.functor
src/category_theory/functor/category.lean
[ "category_theory.natural_transformation", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_inv_hom_app (F : C ⥤ D ⥤ E) {X Y : C} (e : X ≅ Y) (Z : D) : (F.map e.inv).app Z ≫ (F.map e.hom).app Z = 𝟙 _
by simp [← nat_trans.comp_app, ← functor.map_comp]
lemma
category_theory.map_inv_hom_app
category_theory.functor
src/category_theory/functor/category.lean
[ "category_theory.natural_transformation", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
const : C ⥤ (J ⥤ C)
{ obj := λ X, { obj := λ j, X, map := λ j j' f, 𝟙 X }, map := λ X Y f, { app := λ j, f } }
def
category_theory.functor.const
category_theory.functor
src/category_theory/functor/const.lean
[ "category_theory.opposites" ]
[]
The functor sending `X : C` to the constant functor `J ⥤ C` sending everything to `X`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
op_obj_op (X : C) : (const Jᵒᵖ).obj (op X) ≅ ((const J).obj X).op
{ hom := { app := λ j, 𝟙 _ }, inv := { app := λ j, 𝟙 _ } }
def
category_theory.functor.const.op_obj_op
category_theory.functor
src/category_theory/functor/const.lean
[ "category_theory.opposites" ]
[]
The contant functor `Jᵒᵖ ⥤ Cᵒᵖ` sending everything to `op X` is (naturally isomorphic to) the opposite of the constant functor `J ⥤ C` sending everything to `X`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
op_obj_unop (X : Cᵒᵖ) : (const Jᵒᵖ).obj (unop X) ≅ ((const J).obj X).left_op
{ hom := { app := λ j, 𝟙 _ }, inv := { app := λ j, 𝟙 _ } }
def
category_theory.functor.const.op_obj_unop
category_theory.functor
src/category_theory/functor/const.lean
[ "category_theory.opposites" ]
[]
The contant functor `Jᵒᵖ ⥤ C` sending everything to `unop X` is (naturally isomorphic to) the opposite of the constant functor `J ⥤ Cᵒᵖ` sending everything to `X`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
op_obj_unop_hom_app (X : Cᵒᵖ) (j : Jᵒᵖ) : (op_obj_unop.{v₁ v₂} X).hom.app j = 𝟙 _
rfl
lemma
category_theory.functor.const.op_obj_unop_hom_app
category_theory.functor
src/category_theory/functor/const.lean
[ "category_theory.opposites" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
op_obj_unop_inv_app (X : Cᵒᵖ) (j : Jᵒᵖ) : (op_obj_unop.{v₁ v₂} X).inv.app j = 𝟙 _
rfl
lemma
category_theory.functor.const.op_obj_unop_inv_app
category_theory.functor
src/category_theory/functor/const.lean
[ "category_theory.opposites" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unop_functor_op_obj_map (X : Cᵒᵖ) {j₁ j₂ : J} (f : j₁ ⟶ j₂) : (unop ((functor.op (const J)).obj X)).map f = 𝟙 (unop X)
rfl
lemma
category_theory.functor.const.unop_functor_op_obj_map
category_theory.functor
src/category_theory/functor/const.lean
[ "category_theory.opposites" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
const_comp (X : C) (F : C ⥤ D) : (const J).obj X ⋙ F ≅ (const J).obj (F.obj X)
{ hom := { app := λ _, 𝟙 _ }, inv := { app := λ _, 𝟙 _ } }
def
category_theory.functor.const_comp
category_theory.functor
src/category_theory/functor/const.lean
[ "category_theory.opposites" ]
[]
These are actually equal, of course, but not definitionally equal (the equality requires F.map (𝟙 _) = 𝟙 _). A natural isomorphism is more convenient than an equality between functors (compare id_to_iso).
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
uncurry : (C ⥤ (D ⥤ E)) ⥤ ((C × D) ⥤ E)
{ obj := λ F, { obj := λ X, (F.obj X.1).obj X.2, map := λ X Y f, (F.map f.1).app X.2 ≫ (F.obj Y.1).map f.2, map_comp' := λ X Y Z f g, begin simp only [prod_comp_fst, prod_comp_snd, functor.map_comp, nat_trans.comp_app, category.assoc], slice_lhs 2 3 { rw ← nat_trans.naturality...
def
category_theory.uncurry
category_theory.functor
src/category_theory/functor/currying.lean
[ "category_theory.products.bifunctor" ]
[ "functor.map_id" ]
The uncurrying functor, taking a functor `C ⥤ (D ⥤ E)` and producing a functor `(C × D) ⥤ E`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
curry_obj (F : (C × D) ⥤ E) : C ⥤ (D ⥤ E)
{ obj := λ X, { obj := λ Y, F.obj (X, Y), map := λ Y Y' g, F.map (𝟙 X, g) }, map := λ X X' f, { app := λ Y, F.map (f, 𝟙 Y) } }
def
category_theory.curry_obj
category_theory.functor
src/category_theory/functor/currying.lean
[ "category_theory.products.bifunctor" ]
[]
The object level part of the currying functor. (See `curry` for the functorial version.)
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
curry : ((C × D) ⥤ E) ⥤ (C ⥤ (D ⥤ E))
{ obj := λ F, curry_obj F, map := λ F G T, { app := λ X, { app := λ Y, T.app (X, Y), naturality' := λ Y Y' g, begin dsimp [curry_obj], rw nat_trans.naturality, end }, naturality' := λ X X' f, begin ext, dsimp [curry_obj], rw nat_trans.naturality, end } }...
def
category_theory.curry
category_theory.functor
src/category_theory/functor/currying.lean
[ "category_theory.products.bifunctor" ]
[]
The currying functor, taking a functor `(C × D) ⥤ E` and producing a functor `C ⥤ (D ⥤ E)`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
currying : (C ⥤ (D ⥤ E)) ≌ ((C × D) ⥤ E)
equivalence.mk uncurry curry (nat_iso.of_components (λ F, nat_iso.of_components (λ X, nat_iso.of_components (λ Y, iso.refl _) (by tidy)) (by tidy)) (by tidy)) (nat_iso.of_components (λ F, nat_iso.of_components (λ X, eq_to_iso (by simp)) (by tidy)) (by tidy))
def
category_theory.currying
category_theory.functor
src/category_theory/functor/currying.lean
[ "category_theory.products.bifunctor" ]
[]
The equivalence of functor categories given by currying/uncurrying.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
flip_iso_curry_swap_uncurry (F : C ⥤ D ⥤ E) : F.flip ≅ curry.obj (prod.swap _ _ ⋙ uncurry.obj F)
nat_iso.of_components (λ d, nat_iso.of_components (λ c, iso.refl _) (by tidy)) (by tidy)
def
category_theory.flip_iso_curry_swap_uncurry
category_theory.functor
src/category_theory/functor/currying.lean
[ "category_theory.products.bifunctor" ]
[ "prod.swap" ]
`F.flip` is isomorphic to uncurrying `F`, swapping the variables, and currying.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
uncurry_obj_flip (F : C ⥤ D ⥤ E) : uncurry.obj F.flip ≅ prod.swap _ _ ⋙ uncurry.obj F
nat_iso.of_components (λ p, iso.refl _) (by tidy)
def
category_theory.uncurry_obj_flip
category_theory.functor
src/category_theory/functor/currying.lean
[ "category_theory.products.bifunctor" ]
[ "prod.swap" ]
The uncurrying of `F.flip` is isomorphic to swapping the factors followed by the uncurrying of `F`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
whiskering_right₂ : (C ⥤ D ⥤ E) ⥤ ((B ⥤ C) ⥤ (B ⥤ D) ⥤ (B ⥤ E))
uncurry ⋙ (whiskering_right _ _ _) ⋙ ((whiskering_left _ _ _).obj (prod_functor_to_functor_prod _ _ _)) ⋙ curry
def
category_theory.whiskering_right₂
category_theory.functor
src/category_theory/functor/currying.lean
[ "category_theory.products.bifunctor" ]
[]
A version of `category_theory.whiskering_right` for bifunctors, obtained by uncurrying, applying `whiskering_right` and currying back
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
preserves_monomorphisms (F : C ⥤ D) : Prop
(preserves : ∀ {X Y : C} (f : X ⟶ Y) [mono f], mono (F.map f))
class
category_theory.functor.preserves_monomorphisms
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
A functor preserves monomorphisms if it maps monomorphisms to monomorphisms.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_mono (F : C ⥤ D) [preserves_monomorphisms F] {X Y : C} (f : X ⟶ Y) [mono f] : mono (F.map f)
preserves_monomorphisms.preserves f
instance
category_theory.functor.map_mono
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
preserves_epimorphisms (F : C ⥤ D) : Prop
(preserves : ∀ {X Y : C} (f : X ⟶ Y) [epi f], epi (F.map f))
class
category_theory.functor.preserves_epimorphisms
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
A functor preserves epimorphisms if it maps epimorphisms to epimorphisms.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_epi (F : C ⥤ D) [preserves_epimorphisms F] {X Y : C} (f : X ⟶ Y) [epi f] : epi (F.map f)
preserves_epimorphisms.preserves f
instance
category_theory.functor.map_epi
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflects_monomorphisms (F : C ⥤ D) : Prop
(reflects : ∀ {X Y : C} (f : X ⟶ Y), mono (F.map f) → mono f)
class
category_theory.functor.reflects_monomorphisms
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
A functor reflects monomorphisms if morphisms that are mapped to monomorphisms are themselves monomorphisms.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mono_of_mono_map (F : C ⥤ D) [reflects_monomorphisms F] {X Y : C} {f : X ⟶ Y} (h : mono (F.map f)) : mono f
reflects_monomorphisms.reflects f h
lemma
category_theory.functor.mono_of_mono_map
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflects_epimorphisms (F : C ⥤ D) : Prop
(reflects : ∀ {X Y : C} (f : X ⟶ Y), epi (F.map f) → epi f)
class
category_theory.functor.reflects_epimorphisms
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
A functor reflects epimorphisms if morphisms that are mapped to epimorphisms are themselves epimorphisms.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
epi_of_epi_map (F : C ⥤ D) [reflects_epimorphisms F] {X Y : C} {f : X ⟶ Y} (h : epi (F.map f)) : epi f
reflects_epimorphisms.reflects f h
lemma
category_theory.functor.epi_of_epi_map
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
preserves_monomorphisms_comp (F : C ⥤ D) (G : D ⥤ E) [preserves_monomorphisms F] [preserves_monomorphisms G] : preserves_monomorphisms (F ⋙ G)
{ preserves := λ X Y f h, by { rw comp_map, exactI infer_instance } }
instance
category_theory.functor.preserves_monomorphisms_comp
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
preserves_epimorphisms_comp (F : C ⥤ D) (G : D ⥤ E) [preserves_epimorphisms F] [preserves_epimorphisms G] : preserves_epimorphisms (F ⋙ G)
{ preserves := λ X Y f h, by { rw comp_map, exactI infer_instance } }
instance
category_theory.functor.preserves_epimorphisms_comp
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflects_monomorphisms_comp (F : C ⥤ D) (G : D ⥤ E) [reflects_monomorphisms F] [reflects_monomorphisms G] : reflects_monomorphisms (F ⋙ G)
{ reflects := λ X Y f h, (F.mono_of_mono_map (G.mono_of_mono_map h)) }
instance
category_theory.functor.reflects_monomorphisms_comp
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflects_epimorphisms_comp (F : C ⥤ D) (G : D ⥤ E) [reflects_epimorphisms F] [reflects_epimorphisms G] : reflects_epimorphisms (F ⋙ G)
{ reflects := λ X Y f h, (F.epi_of_epi_map (G.epi_of_epi_map h)) }
instance
category_theory.functor.reflects_epimorphisms_comp
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
preserves_epimorphisms_of_preserves_of_reflects (F : C ⥤ D) (G : D ⥤ E) [preserves_epimorphisms (F ⋙ G)] [reflects_epimorphisms G] : preserves_epimorphisms F
⟨λ X Y f hf, G.epi_of_epi_map $ show epi ((F ⋙ G).map f), by exactI infer_instance⟩
lemma
category_theory.functor.preserves_epimorphisms_of_preserves_of_reflects
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
preserves_monomorphisms_of_preserves_of_reflects (F : C ⥤ D) (G : D ⥤ E) [preserves_monomorphisms (F ⋙ G)] [reflects_monomorphisms G] : preserves_monomorphisms F
⟨λ X Y f hf, G.mono_of_mono_map $ show mono ((F ⋙ G).map f), by exactI infer_instance⟩
lemma
category_theory.functor.preserves_monomorphisms_of_preserves_of_reflects
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflects_epimorphisms_of_preserves_of_reflects (F : C ⥤ D) (G : D ⥤ E) [preserves_epimorphisms G] [reflects_epimorphisms (F ⋙ G)] : reflects_epimorphisms F
⟨λ X Y f hf, (F ⋙ G).epi_of_epi_map $ show epi (G.map (F.map f)), by exactI infer_instance⟩
lemma
category_theory.functor.reflects_epimorphisms_of_preserves_of_reflects
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflects_monomorphisms_of_preserves_of_reflects (F : C ⥤ D) (G : D ⥤ E) [preserves_monomorphisms G] [reflects_monomorphisms (F ⋙ G)] : reflects_monomorphisms F
⟨λ X Y f hf, (F ⋙ G).mono_of_mono_map $ show mono (G.map (F.map f)), by exactI infer_instance⟩
lemma
category_theory.functor.reflects_monomorphisms_of_preserves_of_reflects
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
preserves_monomorphisms.of_iso {F G : C ⥤ D} [preserves_monomorphisms F] (α : F ≅ G) : preserves_monomorphisms G
{ preserves := λ X Y f h, begin haveI : mono (F.map f ≫ (α.app Y).hom) := by exactI mono_comp _ _, convert (mono_comp _ _ : mono ((α.app X).inv ≫ F.map f ≫ (α.app Y).hom)), rw [iso.eq_inv_comp, iso.app_hom, iso.app_hom, nat_trans.naturality] end }
lemma
category_theory.functor.preserves_monomorphisms.of_iso
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
preserves_monomorphisms.iso_iff {F G : C ⥤ D} (α : F ≅ G) : preserves_monomorphisms F ↔ preserves_monomorphisms G
⟨λ h, by exactI preserves_monomorphisms.of_iso α, λ h, by exactI preserves_monomorphisms.of_iso α.symm⟩
lemma
category_theory.functor.preserves_monomorphisms.iso_iff
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
preserves_epimorphisms.of_iso {F G : C ⥤ D} [preserves_epimorphisms F] (α : F ≅ G) : preserves_epimorphisms G
{ preserves := λ X Y f h, begin haveI : epi (F.map f ≫ (α.app Y).hom) := by exactI epi_comp _ _, convert (epi_comp _ _ : epi ((α.app X).inv ≫ F.map f ≫ (α.app Y).hom)), rw [iso.eq_inv_comp, iso.app_hom, iso.app_hom, nat_trans.naturality] end }
lemma
category_theory.functor.preserves_epimorphisms.of_iso
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
preserves_epimorphisms.iso_iff {F G : C ⥤ D} (α : F ≅ G) : preserves_epimorphisms F ↔ preserves_epimorphisms G
⟨λ h, by exactI preserves_epimorphisms.of_iso α, λ h, by exactI preserves_epimorphisms.of_iso α.symm⟩
lemma
category_theory.functor.preserves_epimorphisms.iso_iff
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflects_monomorphisms.of_iso {F G : C ⥤ D} [reflects_monomorphisms F] (α : F ≅ G) : reflects_monomorphisms G
{ reflects := λ X Y f h, begin apply F.mono_of_mono_map, haveI : mono (G.map f ≫ (α.app Y).inv) := by exactI mono_comp _ _, convert (mono_comp _ _ : mono ((α.app X).hom ≫ G.map f ≫ (α.app Y).inv)), rw [← category.assoc, iso.eq_comp_inv, iso.app_hom, iso.app_hom, nat_trans.naturality] end }
lemma
category_theory.functor.reflects_monomorphisms.of_iso
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflects_monomorphisms.iso_iff {F G : C ⥤ D} (α : F ≅ G) : reflects_monomorphisms F ↔ reflects_monomorphisms G
⟨λ h, by exactI reflects_monomorphisms.of_iso α, λ h, by exactI reflects_monomorphisms.of_iso α.symm⟩
lemma
category_theory.functor.reflects_monomorphisms.iso_iff
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflects_epimorphisms.of_iso {F G : C ⥤ D} [reflects_epimorphisms F] (α : F ≅ G) : reflects_epimorphisms G
{ reflects := λ X Y f h, begin apply F.epi_of_epi_map, haveI : epi (G.map f ≫ (α.app Y).inv) := by exactI epi_comp _ _, convert (epi_comp _ _ : epi ((α.app X).hom ≫ G.map f ≫ (α.app Y).inv)), rw [← category.assoc, iso.eq_comp_inv, iso.app_hom, iso.app_hom, nat_trans.naturality] end }
lemma
category_theory.functor.reflects_epimorphisms.of_iso
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflects_epimorphisms.iso_iff {F G : C ⥤ D} (α : F ≅ G) : reflects_epimorphisms F ↔ reflects_epimorphisms G
⟨λ h, by exactI reflects_epimorphisms.of_iso α, λ h, by exactI reflects_epimorphisms.of_iso α.symm⟩
lemma
category_theory.functor.reflects_epimorphisms.iso_iff
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
preserves_epimorphsisms_of_adjunction {F : C ⥤ D} {G : D ⥤ C} (adj : F ⊣ G) : preserves_epimorphisms F
{ preserves := λ X Y f hf, ⟨begin introsI Z g h H, replace H := congr_arg (adj.hom_equiv X Z) H, rwa [adj.hom_equiv_naturality_left, adj.hom_equiv_naturality_left, cancel_epi, equiv.apply_eq_iff_eq] at H end⟩ }
lemma
category_theory.functor.preserves_epimorphsisms_of_adjunction
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[ "adj", "equiv.apply_eq_iff_eq" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
preserves_epimorphisms_of_is_left_adjoint (F : C ⥤ D) [is_left_adjoint F] : preserves_epimorphisms F
preserves_epimorphsisms_of_adjunction (adjunction.of_left_adjoint F)
instance
category_theory.functor.preserves_epimorphisms_of_is_left_adjoint
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
preserves_monomorphisms_of_adjunction {F : C ⥤ D} {G : D ⥤ C} (adj : F ⊣ G) : preserves_monomorphisms G
{ preserves := λ X Y f hf, ⟨begin introsI Z g h H, replace H := congr_arg (adj.hom_equiv Z Y).symm H, rwa [adj.hom_equiv_naturality_right_symm, adj.hom_equiv_naturality_right_symm, cancel_mono, equiv.apply_eq_iff_eq] at H end⟩ }
lemma
category_theory.functor.preserves_monomorphisms_of_adjunction
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[ "adj", "equiv.apply_eq_iff_eq" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
preserves_monomorphisms_of_is_right_adjoint (F : C ⥤ D) [is_right_adjoint F] : preserves_monomorphisms F
preserves_monomorphisms_of_adjunction (adjunction.of_right_adjoint F)
instance
category_theory.functor.preserves_monomorphisms_of_is_right_adjoint
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflects_monomorphisms_of_faithful (F : C ⥤ D) [faithful F] : reflects_monomorphisms F
{ reflects := λ X Y f hf, ⟨λ Z g h hgh, by exactI F.map_injective ((cancel_mono (F.map f)).1 (by rw [← F.map_comp, hgh, F.map_comp]))⟩ }
instance
category_theory.functor.reflects_monomorphisms_of_faithful
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflects_epimorphisms_of_faithful (F : C ⥤ D) [faithful F] : reflects_epimorphisms F
{ reflects := λ X Y f hf, ⟨λ Z g h hgh, by exactI F.map_injective ((cancel_epi (F.map f)).1 (by rw [← F.map_comp, hgh, F.map_comp]))⟩ }
instance
category_theory.functor.reflects_epimorphisms_of_faithful
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
split_epi_equiv [full F] [faithful F] : split_epi f ≃ split_epi (F.map f)
{ to_fun := λ f, f.map F, inv_fun := λ s, begin refine ⟨F.preimage s.section_, _⟩, apply F.map_injective, simp only [map_comp, image_preimage, map_id], apply split_epi.id, end, left_inv := by tidy, right_inv := by tidy, }
def
category_theory.functor.split_epi_equiv
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[ "inv_fun", "map_comp", "map_id" ]
If `F` is a fully faithful functor, split epimorphisms are preserved and reflected by `F`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_split_epi_iff [full F] [faithful F] : is_split_epi (F.map f) ↔ is_split_epi f
begin split, { intro h, exact is_split_epi.mk' ((split_epi_equiv F f).inv_fun h.exists_split_epi.some), }, { intro h, exact is_split_epi.mk' ((split_epi_equiv F f).to_fun h.exists_split_epi.some), }, end
lemma
category_theory.functor.is_split_epi_iff
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[ "inv_fun" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
split_mono_equiv [full F] [faithful F] : split_mono f ≃ split_mono (F.map f)
{ to_fun := λ f, f.map F, inv_fun := λ s, begin refine ⟨F.preimage s.retraction, _⟩, apply F.map_injective, simp only [map_comp, image_preimage, map_id], apply split_mono.id, end, left_inv := by tidy, right_inv := by tidy, }
def
category_theory.functor.split_mono_equiv
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[ "inv_fun", "map_comp", "map_id" ]
If `F` is a fully faithful functor, split monomorphisms are preserved and reflected by `F`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_split_mono_iff [full F] [faithful F] : is_split_mono (F.map f) ↔ is_split_mono f
begin split, { intro h, exact is_split_mono.mk' ((split_mono_equiv F f).inv_fun h.exists_split_mono.some), }, { intro h, exact is_split_mono.mk' ((split_mono_equiv F f).to_fun h.exists_split_mono.some), }, end
lemma
category_theory.functor.is_split_mono_iff
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[ "inv_fun" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
epi_map_iff_epi [hF₁ : preserves_epimorphisms F] [hF₂ : reflects_epimorphisms F] : epi (F.map f) ↔ epi f
begin split, { exact F.epi_of_epi_map, }, { introI h, exact F.map_epi f, }, end
lemma
category_theory.functor.epi_map_iff_epi
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mono_map_iff_mono [hF₁ : preserves_monomorphisms F] [hF₂ : reflects_monomorphisms F] : mono (F.map f) ↔ mono f
begin split, { exact F.mono_of_mono_map, }, { introI h, exact F.map_mono f, }, end
lemma
category_theory.functor.mono_map_iff_mono
category_theory.functor
src/category_theory/functor/epi_mono.lean
[ "category_theory.epi_mono", "category_theory.limits.shapes.strong_epi", "category_theory.lifting_properties.adjunction" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83