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is_inverted_by.iff_of_iso (W : morphism_property C) {F₁ F₂ : C ⥤ D} (e : F₁ ≅ F₂) : W.is_inverted_by F₁ ↔ W.is_inverted_by F₂
begin suffices : ∀ (X Y : C) (f : X ⟶ Y), is_iso (F₁.map f) ↔ is_iso (F₂.map f), { split, exact λ h X Y f hf, by { rw ← this, exact h f hf, }, exact λ h X Y f hf, by { rw this, exact h f hf, }, }, intros X Y f, exact (respects_iso.isomorphisms D).arrow_mk_iso_iff (arrow.iso_mk (e.app X) (e.app Y) (b...
lemma
category_theory.morphism_property.is_inverted_by.iff_of_iso
category_theory
src/category_theory/morphism_property.lean
[ "category_theory.limits.shapes.diagonal", "category_theory.arrow", "category_theory.limits.shapes.comm_sq", "category_theory.concrete_category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
diagonal (P : morphism_property C) : morphism_property C
λ X Y f, P (pullback.diagonal f)
def
category_theory.morphism_property.diagonal
category_theory
src/category_theory/morphism_property.lean
[ "category_theory.limits.shapes.diagonal", "category_theory.arrow", "category_theory.limits.shapes.comm_sq", "category_theory.concrete_category.basic" ]
[]
For `P : morphism_property C`, `P.diagonal` is a morphism property that holds for `f : X ⟶ Y` whenever `P` holds for `X ⟶ Y xₓ Y`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
diagonal_iff {X Y : C} {f : X ⟶ Y} : P.diagonal f ↔ P (pullback.diagonal f)
iff.rfl
lemma
category_theory.morphism_property.diagonal_iff
category_theory
src/category_theory/morphism_property.lean
[ "category_theory.limits.shapes.diagonal", "category_theory.arrow", "category_theory.limits.shapes.comm_sq", "category_theory.concrete_category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
respects_iso.diagonal (hP : P.respects_iso) : P.diagonal.respects_iso
begin split, { introv H, rwa [diagonal_iff, pullback.diagonal_comp, hP.cancel_left_is_iso, hP.cancel_left_is_iso, ← hP.cancel_right_is_iso _ _, ← pullback.condition, hP.cancel_left_is_iso], apply_instance }, { introv H, delta diagonal, rwa [pullback.diagonal_comp, hP.cancel_right_is_iso] } e...
lemma
category_theory.morphism_property.respects_iso.diagonal
category_theory
src/category_theory/morphism_property.lean
[ "category_theory.limits.shapes.diagonal", "category_theory.arrow", "category_theory.limits.shapes.comm_sq", "category_theory.concrete_category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
stable_under_composition.diagonal (hP : stable_under_composition P) (hP' : respects_iso P) (hP'' : stable_under_base_change P) : P.diagonal.stable_under_composition
begin introv X h₁ h₂, rw [diagonal_iff, pullback.diagonal_comp], apply hP, { assumption }, rw hP'.cancel_left_is_iso, apply hP''.snd, assumption end
lemma
category_theory.morphism_property.stable_under_composition.diagonal
category_theory
src/category_theory/morphism_property.lean
[ "category_theory.limits.shapes.diagonal", "category_theory.arrow", "category_theory.limits.shapes.comm_sq", "category_theory.concrete_category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
stable_under_base_change.diagonal (hP : stable_under_base_change P) (hP' : respects_iso P) : P.diagonal.stable_under_base_change
stable_under_base_change.mk hP'.diagonal begin introv h, rw [diagonal_iff, diagonal_pullback_fst, hP'.cancel_left_is_iso, hP'.cancel_right_is_iso], convert hP.base_change_map f _ _; simp; assumption end
lemma
category_theory.morphism_property.stable_under_base_change.diagonal
category_theory
src/category_theory/morphism_property.lean
[ "category_theory.limits.shapes.diagonal", "category_theory.arrow", "category_theory.limits.shapes.comm_sq", "category_theory.concrete_category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
universally (P : morphism_property C) : morphism_property C
λ X Y f, ∀ ⦃X' Y' : C⦄ (i₁ : X' ⟶ X) (i₂ : Y' ⟶ Y) (f' : X' ⟶ Y') (h : is_pullback f' i₁ i₂ f), P f'
def
category_theory.morphism_property.universally
category_theory
src/category_theory/morphism_property.lean
[ "category_theory.limits.shapes.diagonal", "category_theory.arrow", "category_theory.limits.shapes.comm_sq", "category_theory.concrete_category.basic" ]
[]
`P.universally` holds for a morphism `f : X ⟶ Y` iff `P` holds for all `X ×[Y] Y' ⟶ Y'`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
universally_respects_iso (P : morphism_property C) : P.universally.respects_iso
begin constructor, { intros X Y Z e f hf X' Z' i₁ i₂ f' H, have : is_pullback (𝟙 _) (i₁ ≫ e.hom) i₁ e.inv := is_pullback.of_horiz_is_iso ⟨by rw [category.id_comp, category.assoc, e.hom_inv_id, category.comp_id]⟩, replace this := this.paste_horiz H, rw [iso.inv_hom_id_assoc, category.id_comp] at t...
lemma
category_theory.morphism_property.universally_respects_iso
category_theory
src/category_theory/morphism_property.lean
[ "category_theory.limits.shapes.diagonal", "category_theory.arrow", "category_theory.limits.shapes.comm_sq", "category_theory.concrete_category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
universally_stable_under_base_change (P : morphism_property C) : P.universally.stable_under_base_change
λ X Y Y' S f g f' g' H h₁ Y'' X'' i₁ i₂ f'' H', h₁ _ _ _ (H'.paste_vert H.flip)
lemma
category_theory.morphism_property.universally_stable_under_base_change
category_theory
src/category_theory/morphism_property.lean
[ "category_theory.limits.shapes.diagonal", "category_theory.arrow", "category_theory.limits.shapes.comm_sq", "category_theory.concrete_category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
stable_under_composition.universally [has_pullbacks C] {P : morphism_property C} (hP : P.stable_under_composition) : P.universally.stable_under_composition
begin intros X Y Z f g hf hg X' Z' i₁ i₂ f' H, have := pullback.lift_fst _ _ (H.w.trans (category.assoc _ _ _).symm), rw ← this at H ⊢, apply hP _ _ _ (hg _ _ _ $ is_pullback.of_has_pullback _ _), exact hf _ _ _ (H.of_right (pullback.lift_snd _ _ _) (is_pullback.of_has_pullback i₂ g)) end
lemma
category_theory.morphism_property.stable_under_composition.universally
category_theory
src/category_theory/morphism_property.lean
[ "category_theory.limits.shapes.diagonal", "category_theory.arrow", "category_theory.limits.shapes.comm_sq", "category_theory.concrete_category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
universally_le (P : morphism_property C) : P.universally ≤ P
begin intros X Y f hf, exact hf (𝟙 _) (𝟙 _) _ (is_pullback.of_vert_is_iso ⟨by rw [category.comp_id, category.id_comp]⟩) end
lemma
category_theory.morphism_property.universally_le
category_theory
src/category_theory/morphism_property.lean
[ "category_theory.limits.shapes.diagonal", "category_theory.arrow", "category_theory.limits.shapes.comm_sq", "category_theory.concrete_category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
stable_under_base_change.universally_eq {P : morphism_property C} (hP : P.stable_under_base_change) : P.universally = P
P.universally_le.antisymm $ λ X Y f hf X' Y' i₁ i₂ f' H, hP H.flip hf
lemma
category_theory.morphism_property.stable_under_base_change.universally_eq
category_theory
src/category_theory/morphism_property.lean
[ "category_theory.limits.shapes.diagonal", "category_theory.arrow", "category_theory.limits.shapes.comm_sq", "category_theory.concrete_category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
universally_mono : monotone (universally : morphism_property C → morphism_property C)
λ P₁ P₂ h X Y f h₁ X' Y' i₁ i₂ f' H, h _ _ _ (h₁ _ _ _ H)
lemma
category_theory.morphism_property.universally_mono
category_theory
src/category_theory/morphism_property.lean
[ "category_theory.limits.shapes.diagonal", "category_theory.arrow", "category_theory.limits.shapes.comm_sq", "category_theory.concrete_category.basic" ]
[ "monotone" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
injective : morphism_property C
λ X Y f, injective f
def
category_theory.morphism_property.injective
category_theory
src/category_theory/morphism_property.lean
[ "category_theory.limits.shapes.diagonal", "category_theory.arrow", "category_theory.limits.shapes.comm_sq", "category_theory.concrete_category.basic" ]
[]
Injectiveness (in a concrete category) as a `morphism_property`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
surjective : morphism_property C
λ X Y f, surjective f
def
category_theory.morphism_property.surjective
category_theory
src/category_theory/morphism_property.lean
[ "category_theory.limits.shapes.diagonal", "category_theory.arrow", "category_theory.limits.shapes.comm_sq", "category_theory.concrete_category.basic" ]
[]
Surjectiveness (in a concrete category) as a `morphism_property`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bijective : morphism_property C
λ X Y f, bijective f
def
category_theory.morphism_property.bijective
category_theory
src/category_theory/morphism_property.lean
[ "category_theory.limits.shapes.diagonal", "category_theory.arrow", "category_theory.limits.shapes.comm_sq", "category_theory.concrete_category.basic" ]
[]
Bijectiveness (in a concrete category) as a `morphism_property`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bijective_eq_sup : morphism_property.bijective C = morphism_property.injective C ⊓ morphism_property.surjective C
rfl
lemma
category_theory.morphism_property.bijective_eq_sup
category_theory
src/category_theory/morphism_property.lean
[ "category_theory.limits.shapes.diagonal", "category_theory.arrow", "category_theory.limits.shapes.comm_sq", "category_theory.concrete_category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
injective_stable_under_composition : (morphism_property.injective C).stable_under_composition
λ X Y Z f g hf hg, by { delta morphism_property.injective, rw coe_comp, exact hg.comp hf }
lemma
category_theory.morphism_property.injective_stable_under_composition
category_theory
src/category_theory/morphism_property.lean
[ "category_theory.limits.shapes.diagonal", "category_theory.arrow", "category_theory.limits.shapes.comm_sq", "category_theory.concrete_category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
surjective_stable_under_composition : (morphism_property.surjective C).stable_under_composition
λ X Y Z f g hf hg, by { delta morphism_property.surjective, rw coe_comp, exact hg.comp hf }
lemma
category_theory.morphism_property.surjective_stable_under_composition
category_theory
src/category_theory/morphism_property.lean
[ "category_theory.limits.shapes.diagonal", "category_theory.arrow", "category_theory.limits.shapes.comm_sq", "category_theory.concrete_category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bijective_stable_under_composition : (morphism_property.bijective C).stable_under_composition
λ X Y Z f g hf hg, by { delta morphism_property.bijective, rw coe_comp, exact hg.comp hf }
lemma
category_theory.morphism_property.bijective_stable_under_composition
category_theory
src/category_theory/morphism_property.lean
[ "category_theory.limits.shapes.diagonal", "category_theory.arrow", "category_theory.limits.shapes.comm_sq", "category_theory.concrete_category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
injective_respects_iso : (morphism_property.injective C).respects_iso
(injective_stable_under_composition C).respects_iso (λ X Y e, ((forget C).map_iso e).to_equiv.injective)
lemma
category_theory.morphism_property.injective_respects_iso
category_theory
src/category_theory/morphism_property.lean
[ "category_theory.limits.shapes.diagonal", "category_theory.arrow", "category_theory.limits.shapes.comm_sq", "category_theory.concrete_category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
surjective_respects_iso : (morphism_property.surjective C).respects_iso
(surjective_stable_under_composition C).respects_iso (λ X Y e, ((forget C).map_iso e).to_equiv.surjective)
lemma
category_theory.morphism_property.surjective_respects_iso
category_theory
src/category_theory/morphism_property.lean
[ "category_theory.limits.shapes.diagonal", "category_theory.arrow", "category_theory.limits.shapes.comm_sq", "category_theory.concrete_category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bijective_respects_iso : (morphism_property.bijective C).respects_iso
(bijective_stable_under_composition C).respects_iso (λ X Y e, ((forget C).map_iso e).to_equiv.bijective)
lemma
category_theory.morphism_property.bijective_respects_iso
category_theory
src/category_theory/morphism_property.lean
[ "category_theory.limits.shapes.diagonal", "category_theory.arrow", "category_theory.limits.shapes.comm_sq", "category_theory.concrete_category.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
app {F G : C ⥤ D} (α : F ≅ G) (X : C) : F.obj X ≅ G.obj X
{ hom := α.hom.app X, inv := α.inv.app X, hom_inv_id' := begin rw [← comp_app, iso.hom_inv_id], refl end, inv_hom_id' := begin rw [← comp_app, iso.inv_hom_id], refl end }
def
category_theory.iso.app
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
The application of a natural isomorphism to an object. We put this definition in a different namespace, so that we can use `α.app`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
hom_inv_id_app {F G : C ⥤ D} (α : F ≅ G) (X : C) : α.hom.app X ≫ α.inv.app X = 𝟙 (F.obj X)
congr_fun (congr_arg nat_trans.app α.hom_inv_id) X
lemma
category_theory.iso.hom_inv_id_app
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_hom_id_app {F G : C ⥤ D} (α : F ≅ G) (X : C) : α.inv.app X ≫ α.hom.app X = 𝟙 (G.obj X)
congr_fun (congr_arg nat_trans.app α.inv_hom_id) X
lemma
category_theory.iso.inv_hom_id_app
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
trans_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_iso.trans_app
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
app_hom {F G : C ⥤ D} (α : F ≅ G) (X : C) : (α.app X).hom = α.hom.app X
rfl
lemma
category_theory.nat_iso.app_hom
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
app_inv {F G : C ⥤ D} (α : F ≅ G) (X : C) : (α.app X).inv = α.inv.app X
rfl
lemma
category_theory.nat_iso.app_inv
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
hom_app_is_iso (α : F ≅ G) (X : C) : is_iso (α.hom.app X)
⟨⟨α.inv.app X, ⟨by rw [←comp_app, iso.hom_inv_id, ←id_app], by rw [←comp_app, iso.inv_hom_id, ←id_app]⟩⟩⟩
instance
category_theory.nat_iso.hom_app_is_iso
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_app_is_iso (α : F ≅ G) (X : C) : is_iso (α.inv.app X)
⟨⟨α.hom.app X, ⟨by rw [←comp_app, iso.inv_hom_id, ←id_app], by rw [←comp_app, iso.hom_inv_id, ←id_app]⟩⟩⟩
instance
category_theory.nat_iso.inv_app_is_iso
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cancel_nat_iso_hom_left {X : C} {Z : D} (g g' : G.obj X ⟶ Z) : α.hom.app X ≫ g = α.hom.app X ≫ g' ↔ g = g'
by simp only [cancel_epi]
lemma
category_theory.nat_iso.cancel_nat_iso_hom_left
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cancel_nat_iso_inv_left {X : C} {Z : D} (g g' : F.obj X ⟶ Z) : α.inv.app X ≫ g = α.inv.app X ≫ g' ↔ g = g'
by simp only [cancel_epi]
lemma
category_theory.nat_iso.cancel_nat_iso_inv_left
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cancel_nat_iso_hom_right {X : D} {Y : C} (f f' : X ⟶ F.obj Y) : f ≫ α.hom.app Y = f' ≫ α.hom.app Y ↔ f = f'
by simp only [cancel_mono]
lemma
category_theory.nat_iso.cancel_nat_iso_hom_right
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cancel_nat_iso_inv_right {X : D} {Y : C} (f f' : X ⟶ G.obj Y) : f ≫ α.inv.app Y = f' ≫ α.inv.app Y ↔ f = f'
by simp only [cancel_mono]
lemma
category_theory.nat_iso.cancel_nat_iso_inv_right
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cancel_nat_iso_hom_right_assoc {W X X' : D} {Y : C} (f : W ⟶ X) (g : X ⟶ F.obj Y) (f' : W ⟶ X') (g' : X' ⟶ F.obj Y) : f ≫ g ≫ α.hom.app Y = f' ≫ g' ≫ α.hom.app Y ↔ f ≫ g = f' ≫ g'
by simp only [←category.assoc, cancel_mono]
lemma
category_theory.nat_iso.cancel_nat_iso_hom_right_assoc
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cancel_nat_iso_inv_right_assoc {W X X' : D} {Y : C} (f : W ⟶ X) (g : X ⟶ G.obj Y) (f' : W ⟶ X') (g' : X' ⟶ G.obj Y) : f ≫ g ≫ α.inv.app Y = f' ≫ g' ≫ α.inv.app Y ↔ f ≫ g = f' ≫ g'
by simp only [←category.assoc, cancel_mono]
lemma
category_theory.nat_iso.cancel_nat_iso_inv_right_assoc
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_inv_app {F G : C ⥤ D} (e : F ≅ G) (X : C) : inv (e.inv.app X) = e.hom.app X
by { ext, simp }
lemma
category_theory.nat_iso.inv_inv_app
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
naturality_1 (α : F ≅ G) (f : X ⟶ Y) : α.inv.app X ≫ F.map f ≫ α.hom.app Y = G.map f
by simp
lemma
category_theory.nat_iso.naturality_1
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
naturality_2 (α : F ≅ G) (f : X ⟶ Y) : α.hom.app X ≫ G.map f ≫ α.inv.app Y = F.map f
by simp
lemma
category_theory.nat_iso.naturality_2
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
naturality_1' (α : F ⟶ G) (f : X ⟶ Y) [is_iso (α.app X)] : inv (α.app X) ≫ F.map f ≫ α.app Y = G.map f
by simp
lemma
category_theory.nat_iso.naturality_1'
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
naturality_2' (α : F ⟶ G) (f : X ⟶ Y) [is_iso (α.app Y)] : α.app X ≫ G.map f ≫ inv (α.app Y) = F.map f
by rw [←category.assoc, ←naturality, category.assoc, is_iso.hom_inv_id, category.comp_id]
lemma
category_theory.nat_iso.naturality_2'
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_iso_app_of_is_iso (α : F ⟶ G) [is_iso α] (X) : is_iso (α.app X)
⟨⟨(inv α).app X, ⟨congr_fun (congr_arg nat_trans.app (is_iso.hom_inv_id α)) X, congr_fun (congr_arg nat_trans.app (is_iso.inv_hom_id α)) X⟩⟩⟩
instance
category_theory.nat_iso.is_iso_app_of_is_iso
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
The components of a natural isomorphism are isomorphisms.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_iso_inv_app (α : F ⟶ G) [is_iso α] (X) : (inv α).app X = inv (α.app X)
by { ext, rw ←nat_trans.comp_app, simp, }
lemma
category_theory.nat_iso.is_iso_inv_app
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_map_inv_app (F : C ⥤ D ⥤ E) {X Y : C} (e : X ≅ Y) (Z : D) : inv ((F.map e.inv).app Z) = (F.map e.hom).app Z
by { ext, simp, }
lemma
category_theory.nat_iso.inv_map_inv_app
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_components (app : ∀ X : C, F.obj X ≅ G.obj X) (naturality : ∀ {X Y : C} (f : X ⟶ Y), F.map f ≫ (app Y).hom = (app X).hom ≫ G.map f) : F ≅ G
{ hom := { app := λ X, (app X).hom }, inv := { app := λ X, (app X).inv, naturality' := λ X Y f, begin have h := congr_arg (λ f, (app X).inv ≫ (f ≫ (app Y).inv)) (naturality f).symm, simp only [iso.inv_hom_id_assoc, iso.hom_inv_id, assoc, comp_id, cancel_mono] at h, exact h end }, }
def
category_theory.nat_iso.of_components
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
Construct a natural isomorphism between functors by giving object level isomorphisms, and checking naturality only in the forward direction.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_components.app (app' : ∀ X : C, F.obj X ≅ G.obj X) (naturality) (X) : (of_components app' naturality).app X = app' X
by tidy
lemma
category_theory.nat_iso.of_components.app
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_iso_of_is_iso_app (α : F ⟶ G) [∀ X : C, is_iso (α.app X)] : is_iso α
⟨(is_iso.of_iso (of_components (λ X, as_iso (α.app X)) (by tidy))).1⟩
lemma
category_theory.nat_iso.is_iso_of_is_iso_app
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
hcomp {F G : C ⥤ D} {H I : D ⥤ E} (α : F ≅ G) (β : H ≅ I) : F ⋙ H ≅ G ⋙ I
begin refine ⟨α.hom ◫ β.hom, α.inv ◫ β.inv, _, _⟩, { ext, rw [←nat_trans.exchange], simp, refl }, ext, rw [←nat_trans.exchange], simp, refl end
def
category_theory.nat_iso.hcomp
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
Horizontal composition of natural isomorphisms.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_iso_map_iff {F₁ F₂ : C ⥤ D} (e : F₁ ≅ F₂) {X Y : C} (f : X ⟶ Y) : is_iso (F₁.map f) ↔ is_iso (F₂.map f)
begin revert F₁ F₂, suffices : ∀ {F₁ F₂ : C ⥤ D} (e : F₁ ≅ F₂) (hf : is_iso (F₁.map f)), is_iso (F₂.map f), { exact λ F₁ F₂ e, ⟨this e, this e.symm⟩, }, introsI F₁ F₂ e hf, refine is_iso.mk ⟨e.inv.app Y ≫ inv (F₁.map f) ≫ e.hom.app X, _, _⟩, { simp only [nat_trans.naturality_assoc, is_iso.hom_inv_id_assoc, ...
lemma
category_theory.nat_iso.is_iso_map_iff
category_theory
src/category_theory/natural_isomorphism.lean
[ "category_theory.functor.category", "category_theory.isomorphism" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nat_trans (F G : C ⥤ D) : Type (max u₁ v₂)
(app : Π X : C, F.obj X ⟶ G.obj X) (naturality' : ∀ ⦃X Y : C⦄ (f : X ⟶ Y), F.map f ≫ app Y = app X ≫ G.map f . obviously)
structure
category_theory.nat_trans
category_theory
src/category_theory/natural_transformation.lean
[ "category_theory.functor.basic" ]
[]
`nat_trans F G` represents a natural transformation between functors `F` and `G`. The field `app` provides the components of the natural transformation. Naturality is expressed by `α.naturality_lemma`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
congr_app {F G : C ⥤ D} {α β : nat_trans F G} (h : α = β) (X : C) : α.app X = β.app X
congr_fun (congr_arg nat_trans.app h) X
lemma
category_theory.congr_app
category_theory
src/category_theory/natural_transformation.lean
[ "category_theory.functor.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
id (F : C ⥤ D) : nat_trans F F
{ app := λ X, 𝟙 (F.obj X) }
def
category_theory.nat_trans.id
category_theory
src/category_theory/natural_transformation.lean
[ "category_theory.functor.basic" ]
[]
`nat_trans.id F` is the identity natural transformation on a functor `F`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
id_app' (F : C ⥤ D) (X : C) : (nat_trans.id F).app X = 𝟙 (F.obj X)
rfl
lemma
category_theory.nat_trans.id_app'
category_theory
src/category_theory/natural_transformation.lean
[ "category_theory.functor.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
vcomp (α : nat_trans F G) (β : nat_trans G H) : nat_trans F H
{ app := λ X, (α.app X) ≫ (β.app X) }
def
category_theory.nat_trans.vcomp
category_theory
src/category_theory/natural_transformation.lean
[ "category_theory.functor.basic" ]
[]
`vcomp α β` is the vertical compositions of natural transformations.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
vcomp_app (α : nat_trans F G) (β : nat_trans G H) (X : C) : (vcomp α β).app X = (α.app X) ≫ (β.app X)
rfl
lemma
category_theory.nat_trans.vcomp_app
category_theory
src/category_theory/natural_transformation.lean
[ "category_theory.functor.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
noetherian_object (X : C) : Prop
(subobject_gt_well_founded : well_founded ((>) : subobject X → subobject X → Prop))
class
category_theory.noetherian_object
category_theory
src/category_theory/noetherian.lean
[ "category_theory.subobject.lattice", "category_theory.essentially_small", "category_theory.simple" ]
[]
A noetherian object is an object which does not have infinite increasing sequences of subobjects. See https://stacks.math.columbia.edu/tag/0FCG
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
artinian_object (X : C) : Prop
(subobject_lt_well_founded [] : well_founded ((<) : subobject X → subobject X → Prop))
class
category_theory.artinian_object
category_theory
src/category_theory/noetherian.lean
[ "category_theory.subobject.lattice", "category_theory.essentially_small", "category_theory.simple" ]
[]
An artinian object is an object which does not have infinite decreasing sequences of subobjects. See https://stacks.math.columbia.edu/tag/0FCF
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
noetherian extends essentially_small C
(noetherian_object : ∀ (X : C), noetherian_object X)
class
category_theory.noetherian
category_theory
src/category_theory/noetherian.lean
[ "category_theory.subobject.lattice", "category_theory.essentially_small", "category_theory.simple" ]
[]
A category is noetherian if it is essentially small and all objects are noetherian.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
artinian extends essentially_small C
(artinian_object : ∀ (X : C), artinian_object X)
class
category_theory.artinian
category_theory
src/category_theory/noetherian.lean
[ "category_theory.subobject.lattice", "category_theory.essentially_small", "category_theory.simple" ]
[]
A category is artinian if it is essentially small and all objects are artinian.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
exists_simple_subobject {X : C} [artinian_object X] (h : ¬ is_zero X) : ∃ (Y : subobject X), simple (Y : C)
begin haveI : nontrivial (subobject X) := nontrivial_of_not_is_zero h, haveI := is_atomic_of_order_bot_well_founded_lt (artinian_object.subobject_lt_well_founded X), have := is_atomic.eq_bot_or_exists_atom_le (⊤ : subobject X), obtain ⟨Y, s⟩ := (is_atomic.eq_bot_or_exists_atom_le (⊤ : subobject X)).resolve_left...
lemma
category_theory.exists_simple_subobject
category_theory
src/category_theory/noetherian.lean
[ "category_theory.subobject.lattice", "category_theory.essentially_small", "category_theory.simple" ]
[ "is_atomic_of_order_bot_well_founded_lt", "nontrivial", "top_ne_bot" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
simple_subobject {X : C} [artinian_object X] (h : ¬ is_zero X) : C
(exists_simple_subobject h).some
def
category_theory.simple_subobject
category_theory
src/category_theory/noetherian.lean
[ "category_theory.subobject.lattice", "category_theory.essentially_small", "category_theory.simple" ]
[]
Choose an arbitrary simple subobject of a non-zero artinian object.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
simple_subobject_arrow {X : C} [artinian_object X] (h : ¬ is_zero X) : simple_subobject h ⟶ X
(exists_simple_subobject h).some.arrow
def
category_theory.simple_subobject_arrow
category_theory
src/category_theory/noetherian.lean
[ "category_theory.subobject.lattice", "category_theory.essentially_small", "category_theory.simple" ]
[]
The monomorphism from the arbitrary simple subobject of a non-zero artinian object.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
quiver.hom.op_inj {X Y : C} : function.injective (quiver.hom.op : (X ⟶ Y) → (op Y ⟶ op X))
λ _ _ H, congr_arg quiver.hom.unop H
lemma
quiver.hom.op_inj
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[ "quiver.hom.op", "quiver.hom.unop" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
quiver.hom.unop_inj {X Y : Cᵒᵖ} : function.injective (quiver.hom.unop : (X ⟶ Y) → (unop Y ⟶ unop X))
λ _ _ H, congr_arg quiver.hom.op H
lemma
quiver.hom.unop_inj
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[ "quiver.hom.op", "quiver.hom.unop" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
quiver.hom.unop_op {X Y : C} (f : X ⟶ Y) : f.op.unop = f
rfl
lemma
quiver.hom.unop_op
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
quiver.hom.op_unop {X Y : Cᵒᵖ} (f : X ⟶ Y) : f.unop.op = f
rfl
lemma
quiver.hom.op_unop
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
category.opposite : category.{v₁} Cᵒᵖ
{ comp := λ _ _ _ f g, (g.unop ≫ f.unop).op, id := λ X, (𝟙 (unop X)).op }
instance
category_theory.category.opposite
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
The opposite category. See <https://stacks.math.columbia.edu/tag/001M>.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
op_comp {X Y Z : C} {f : X ⟶ Y} {g : Y ⟶ Z} : (f ≫ g).op = g.op ≫ f.op
rfl
lemma
category_theory.op_comp
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
op_id {X : C} : (𝟙 X).op = 𝟙 (op X)
rfl
lemma
category_theory.op_id
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unop_comp {X Y Z : Cᵒᵖ} {f : X ⟶ Y} {g : Y ⟶ Z} : (f ≫ g).unop = g.unop ≫ f.unop
rfl
lemma
category_theory.unop_comp
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unop_id {X : Cᵒᵖ} : (𝟙 X).unop = 𝟙 (unop X)
rfl
lemma
category_theory.unop_id
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unop_id_op {X : C} : (𝟙 (op X)).unop = 𝟙 X
rfl
lemma
category_theory.unop_id_op
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
op_id_unop {X : Cᵒᵖ} : (𝟙 (unop X)).op = 𝟙 X
rfl
lemma
category_theory.op_id_unop
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
op_op : (Cᵒᵖ)ᵒᵖ ⥤ C
{ obj := λ X, unop (unop X), map := λ X Y f, f.unop.unop }
def
category_theory.op_op
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
The functor from the double-opposite of a category to the underlying category.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unop_unop : C ⥤ Cᵒᵖᵒᵖ
{ obj := λ X, op (op X), map := λ X Y f, f.op.op }
def
category_theory.unop_unop
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
The functor from a category to its double-opposite.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
op_op_equivalence : Cᵒᵖᵒᵖ ≌ C
{ functor := op_op C, inverse := unop_unop C, unit_iso := iso.refl (𝟭 Cᵒᵖᵒᵖ), counit_iso := iso.refl (unop_unop C ⋙ op_op C) }
def
category_theory.op_op_equivalence
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
The double opposite category is equivalent to the original.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_iso_op {X Y : C} (f : X ⟶ Y) [is_iso f] : is_iso f.op
⟨⟨(inv f).op, ⟨quiver.hom.unop_inj (by tidy), quiver.hom.unop_inj (by tidy)⟩⟩⟩
instance
category_theory.is_iso_op
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[ "quiver.hom.unop_inj" ]
If `f` is an isomorphism, so is `f.op`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_iso_of_op {X Y : C} (f : X ⟶ Y) [is_iso f.op] : is_iso f
⟨⟨(inv (f.op)).unop, ⟨quiver.hom.op_inj (by simp), quiver.hom.op_inj (by simp)⟩⟩⟩
lemma
category_theory.is_iso_of_op
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[ "quiver.hom.op_inj" ]
If `f.op` is an isomorphism `f` must be too. (This cannot be an instance as it would immediately loop!)
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_iso_op_iff {X Y : C} (f : X ⟶ Y) : is_iso f.op ↔ is_iso f
⟨λ hf, by exactI is_iso_of_op _, λ hf, by exactI infer_instance⟩
lemma
category_theory.is_iso_op_iff
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_iso_unop_iff {X Y : Cᵒᵖ} (f : X ⟶ Y) : is_iso f.unop ↔ is_iso f
by rw [← is_iso_op_iff f.unop, quiver.hom.op_unop]
lemma
category_theory.is_iso_unop_iff
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[ "quiver.hom.op_unop" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_iso_unop {X Y : Cᵒᵖ} (f : X ⟶ Y) [is_iso f] : is_iso f.unop
(is_iso_unop_iff _).2 infer_instance
instance
category_theory.is_iso_unop
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
op_inv {X Y : C} (f : X ⟶ Y) [is_iso f] : (inv f).op = inv f.op
by { ext, rw [← op_comp, is_iso.inv_hom_id, op_id] }
lemma
category_theory.op_inv
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unop_inv {X Y : Cᵒᵖ} (f : X ⟶ Y) [is_iso f] : (inv f).unop = inv f.unop
by { ext, rw [← unop_comp, is_iso.inv_hom_id, unop_id] }
lemma
category_theory.unop_inv
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
op (F : C ⥤ D) : Cᵒᵖ ⥤ Dᵒᵖ
{ obj := λ X, op (F.obj (unop X)), map := λ X Y f, (F.map f.unop).op }
def
category_theory.functor.op
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
The opposite of a functor, i.e. considering a functor `F : C ⥤ D` as a functor `Cᵒᵖ ⥤ Dᵒᵖ`. In informal mathematics no distinction is made between these.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unop (F : Cᵒᵖ ⥤ Dᵒᵖ) : C ⥤ D
{ obj := λ X, unop (F.obj (op X)), map := λ X Y f, (F.map f.op).unop }
def
category_theory.functor.unop
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
Given a functor `F : Cᵒᵖ ⥤ Dᵒᵖ` we can take the "unopposite" functor `F : C ⥤ D`. In informal mathematics no distinction is made between these.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
op_unop_iso (F : C ⥤ D) : F.op.unop ≅ F
nat_iso.of_components (λ X, iso.refl _) (by tidy)
def
category_theory.functor.op_unop_iso
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
The isomorphism between `F.op.unop` and `F`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unop_op_iso (F : Cᵒᵖ ⥤ Dᵒᵖ) : F.unop.op ≅ F
nat_iso.of_components (λ X, iso.refl _) (by tidy)
def
category_theory.functor.unop_op_iso
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
The isomorphism between `F.unop.op` and `F`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
op_hom : (C ⥤ D)ᵒᵖ ⥤ (Cᵒᵖ ⥤ Dᵒᵖ)
{ obj := λ F, (unop F).op, map := λ F G α, { app := λ X, (α.unop.app (unop X)).op, naturality' := λ X Y f, quiver.hom.unop_inj (α.unop.naturality f.unop).symm } }
def
category_theory.functor.op_hom
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[ "quiver.hom.unop_inj" ]
Taking the opposite of a functor is functorial.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
op_inv : (Cᵒᵖ ⥤ Dᵒᵖ) ⥤ (C ⥤ D)ᵒᵖ
{ obj := λ F, op F.unop, map := λ F G α, quiver.hom.op { app := λ X, (α.app (op X)).unop, naturality' := λ X Y f, quiver.hom.op_inj $ (α.naturality f.op).symm } }
def
category_theory.functor.op_inv
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[ "quiver.hom.op", "quiver.hom.op_inj" ]
Take the "unopposite" of a functor is functorial.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
left_op (F : C ⥤ Dᵒᵖ) : Cᵒᵖ ⥤ D
{ obj := λ X, unop (F.obj (unop X)), map := λ X Y f, (F.map f.unop).unop }
def
category_theory.functor.left_op
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
Another variant of the opposite of functor, turning a functor `C ⥤ Dᵒᵖ` into a functor `Cᵒᵖ ⥤ D`. In informal mathematics no distinction is made.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
right_op (F : Cᵒᵖ ⥤ D) : C ⥤ Dᵒᵖ
{ obj := λ X, op (F.obj (op X)), map := λ X Y f, (F.map f.op).op }
def
category_theory.functor.right_op
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
Another variant of the opposite of functor, turning a functor `Cᵒᵖ ⥤ D` into a functor `C ⥤ Dᵒᵖ`. In informal mathematics no distinction is made.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
right_op_faithful {F : Cᵒᵖ ⥤ D} [faithful F] : faithful F.right_op
{ map_injective' := λ X Y f g h, quiver.hom.op_inj (map_injective F (quiver.hom.op_inj h)) }
instance
category_theory.functor.right_op_faithful
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[ "quiver.hom.op_inj" ]
If F is faithful then the right_op of F is also faithful.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
left_op_faithful {F : C ⥤ Dᵒᵖ} [faithful F] : faithful F.left_op
{ map_injective' := λ X Y f g h, quiver.hom.unop_inj (map_injective F (quiver.hom.unop_inj h)) }
instance
category_theory.functor.left_op_faithful
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[ "quiver.hom.unop_inj" ]
If F is faithful then the left_op of F is also faithful.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
left_op_right_op_iso (F : C ⥤ Dᵒᵖ) : F.left_op.right_op ≅ F
nat_iso.of_components (λ X, iso.refl _) (by tidy)
def
category_theory.functor.left_op_right_op_iso
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
The isomorphism between `F.left_op.right_op` and `F`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
right_op_left_op_iso (F : Cᵒᵖ ⥤ D) : F.right_op.left_op ≅ F
nat_iso.of_components (λ X, iso.refl _) (by tidy)
def
category_theory.functor.right_op_left_op_iso
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
The isomorphism between `F.right_op.left_op` and `F`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
right_op_left_op_eq (F : Cᵒᵖ ⥤ D) : F.right_op.left_op = F
by { cases F, refl, }
lemma
category_theory.functor.right_op_left_op_eq
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
Whenever possible, it is advisable to use the isomorphism `right_op_left_op_iso` instead of this equality of functors.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
op (α : F ⟶ G) : G.op ⟶ F.op
{ app := λ X, (α.app (unop X)).op, naturality' := λ X Y f, quiver.hom.unop_inj (by simp) }
def
category_theory.nat_trans.op
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[ "quiver.hom.unop_inj" ]
The opposite of a natural transformation.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
op_id (F : C ⥤ D) : nat_trans.op (𝟙 F) = 𝟙 (F.op)
rfl
lemma
category_theory.nat_trans.op_id
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unop {F G : Cᵒᵖ ⥤ Dᵒᵖ} (α : F ⟶ G) : G.unop ⟶ F.unop
{ app := λ X, (α.app (op X)).unop, naturality' := λ X Y f, quiver.hom.op_inj (by simp) }
def
category_theory.nat_trans.unop
category_theory
src/category_theory/opposites.lean
[ "category_theory.equivalence" ]
[ "quiver.hom.op_inj" ]
The "unopposite" of a natural transformation.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83