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vertex_group_isom_of_map {c d : C} (f : c ⟶ d) : (c ⟶ c) ≃* (d ⟶ d)
{ to_fun := λ γ, inv f ≫ γ ≫ f, inv_fun := λ δ, f ≫ δ ≫ inv f, left_inv := λ γ, by simp_rw [category.assoc, comp_inv, category.comp_id, ←category.assoc, comp_inv, category.id_comp], right_inv := λ δ, by simp_rw [category.assoc, inv_comp, ←category.assoc, ...
def
category_theory.groupoid.vertex_group_isom_of_map
category_theory.groupoid
src/category_theory/groupoid/vertex_group.lean
[ "category_theory.groupoid", "category_theory.path_category", "algebra.group.defs", "algebra.hom.group", "algebra.hom.equiv.basic", "combinatorics.quiver.path" ]
[ "inv_fun" ]
An arrow in the groupoid defines, by conjugation, an isomorphism of groups between its endpoints.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
vertex_group_isom_of_path {c d : C} (p : quiver.path c d) : (c ⟶ c) ≃* (d ⟶ d)
vertex_group_isom_of_map (compose_path p)
def
category_theory.groupoid.vertex_group_isom_of_path
category_theory.groupoid
src/category_theory/groupoid/vertex_group.lean
[ "category_theory.groupoid", "category_theory.path_category", "algebra.group.defs", "algebra.hom.group", "algebra.hom.equiv.basic", "combinatorics.quiver.path" ]
[ "quiver.path" ]
A path in the groupoid defines an isomorphism between its endpoints.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.category_theory.functor.map_vertex_group {D : Type v} [groupoid D] (φ : C ⥤ D) (c : C) : (c ⟶ c) →* (φ.obj c ⟶ φ.obj c)
{ to_fun := φ.map, map_one' := φ.map_id c, map_mul' := φ.map_comp }
def
category_theory.functor.map_vertex_group
category_theory.groupoid
src/category_theory/groupoid/vertex_group.lean
[ "category_theory.groupoid", "category_theory.path_category", "algebra.group.defs", "algebra.hom.group", "algebra.hom.equiv.basic", "combinatorics.quiver.path" ]
[]
A functor defines a morphism of vertex group.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_idempotent_complete : Prop
(idempotents_split : ∀ (X : C) (p : X ⟶ X), p ≫ p = p → ∃ (Y : C) (i : Y ⟶ X) (e : X ⟶ Y), i ≫ e = 𝟙 Y ∧ e ≫ i = p)
class
category_theory.is_idempotent_complete
category_theory.idempotents
src/category_theory/idempotents/basic.lean
[ "category_theory.abelian.basic" ]
[]
A category is idempotent complete iff all idempotent endomorphisms `p` split as a composition `p = e ≫ i` with `i ≫ e = 𝟙 _`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_idempotent_complete_iff_has_equalizer_of_id_and_idempotent : is_idempotent_complete C ↔ ∀ (X : C) (p : X ⟶ X), p ≫ p = p → has_equalizer (𝟙 X) p
begin split, { introI, intros X p hp, rcases is_idempotent_complete.idempotents_split X p hp with ⟨Y, i, e, ⟨h₁, h₂⟩⟩, exact ⟨nonempty.intro { cone := fork.of_ι i (show i ≫ 𝟙 X = i ≫ p, by rw [comp_id, ← h₂, ← assoc, h₁, id_comp]), is_limit := begin apply fork.is_limit...
lemma
category_theory.idempotents.is_idempotent_complete_iff_has_equalizer_of_id_and_idempotent
category_theory.idempotents
src/category_theory/idempotents/basic.lean
[ "category_theory.abelian.basic" ]
[]
A category is idempotent complete iff for all idempotent endomorphisms, the equalizer of the identity and this idempotent exists.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
idem_of_id_sub_idem [preadditive C] {X : C} (p : X ⟶ X) (hp : p ≫ p = p) : (𝟙 _ - p) ≫ (𝟙 _ - p) = (𝟙 _ - p)
by simp only [comp_sub, sub_comp, id_comp, comp_id, hp, sub_self, sub_zero]
lemma
category_theory.idempotents.idem_of_id_sub_idem
category_theory.idempotents
src/category_theory/idempotents/basic.lean
[ "category_theory.abelian.basic" ]
[]
In a preadditive category, when `p : X ⟶ X` is idempotent, then `𝟙 X - p` is also idempotent.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_idempotent_complete_iff_idempotents_have_kernels [preadditive C] : is_idempotent_complete C ↔ ∀ (X : C) (p : X ⟶ X), p ≫ p = p → has_kernel p
begin rw is_idempotent_complete_iff_has_equalizer_of_id_and_idempotent, split, { intros h X p hp, haveI := h X (𝟙 _ - p) (idem_of_id_sub_idem p hp), convert has_kernel_of_has_equalizer (𝟙 X) (𝟙 X - p), rw [sub_sub_cancel], }, { intros h X p hp, haveI : has_kernel (𝟙 _ - p) := h X (𝟙 _ - p) ...
lemma
category_theory.idempotents.is_idempotent_complete_iff_idempotents_have_kernels
category_theory.idempotents
src/category_theory/idempotents/basic.lean
[ "category_theory.abelian.basic" ]
[]
A preadditive category is pseudoabelian iff all idempotent endomorphisms have a kernel.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_idempotent_complete_of_abelian (D : Type*) [category D] [abelian D] : is_idempotent_complete D
by { rw is_idempotent_complete_iff_idempotents_have_kernels, intros, apply_instance, }
instance
category_theory.idempotents.is_idempotent_complete_of_abelian
category_theory.idempotents
src/category_theory/idempotents/basic.lean
[ "category_theory.abelian.basic" ]
[]
An abelian category is idempotent complete.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
split_imp_of_iso {X X' : C} (φ : X ≅ X') (p : X ⟶ X) (p' : X' ⟶ X') (hpp' : p ≫ φ.hom = φ.hom ≫ p') (h : ∃ (Y : C) (i : Y ⟶ X) (e : X ⟶ Y), i ≫ e = 𝟙 Y ∧ e ≫ i = p) : (∃ (Y' : C) (i' : Y' ⟶ X') (e' : X' ⟶ Y'), i' ≫ e' = 𝟙 Y' ∧ e' ≫ i' = p')
begin rcases h with ⟨Y, i, e, ⟨h₁, h₂⟩⟩, use [Y, i ≫ φ.hom, φ.inv ≫ e], split, { slice_lhs 2 3 { rw φ.hom_inv_id, }, rw [id_comp, h₁], }, { slice_lhs 2 3 { rw h₂, }, rw [hpp', ← assoc, φ.inv_hom_id, id_comp], } end
lemma
category_theory.idempotents.split_imp_of_iso
category_theory.idempotents
src/category_theory/idempotents/basic.lean
[ "category_theory.abelian.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
split_iff_of_iso {X X' : C} (φ : X ≅ X') (p : X ⟶ X) (p' : X' ⟶ X') (hpp' : p ≫ φ.hom = φ.hom ≫ p') : (∃ (Y : C) (i : Y ⟶ X) (e : X ⟶ Y), i ≫ e = 𝟙 Y ∧ e ≫ i = p) ↔ (∃ (Y' : C) (i' : Y' ⟶ X') (e' : X' ⟶ Y'), i' ≫ e' = 𝟙 Y' ∧ e' ≫ i' = p')
begin split, { exact split_imp_of_iso φ p p' hpp', }, { apply split_imp_of_iso φ.symm p' p, rw [← comp_id p, ← φ.hom_inv_id], slice_rhs 2 3 { rw hpp', }, slice_rhs 1 2 { erw φ.inv_hom_id, }, simpa only [id_comp], }, end
lemma
category_theory.idempotents.split_iff_of_iso
category_theory.idempotents
src/category_theory/idempotents/basic.lean
[ "category_theory.abelian.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equivalence.is_idempotent_complete {D : Type*} [category D] (ε : C ≌ D) (h : is_idempotent_complete C) : is_idempotent_complete D
begin refine ⟨_⟩, intros X' p hp, let φ := ε.counit_iso.symm.app X', erw split_iff_of_iso φ p (φ.inv ≫ p ≫ φ.hom) (by { slice_rhs 1 2 { rw φ.hom_inv_id, }, rw id_comp,}), rcases is_idempotent_complete.idempotents_split (ε.inverse.obj X') (ε.inverse.map p) (by rw [← ε.inverse.map_comp, hp]) with ⟨Y, i,...
lemma
category_theory.idempotents.equivalence.is_idempotent_complete
category_theory.idempotents
src/category_theory/idempotents/basic.lean
[ "category_theory.abelian.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_idempotent_complete_iff_of_equivalence {D : Type*} [category D] (ε : C ≌ D) : is_idempotent_complete C ↔ is_idempotent_complete D
begin split, { exact equivalence.is_idempotent_complete ε, }, { exact equivalence.is_idempotent_complete ε.symm, }, end
lemma
category_theory.idempotents.is_idempotent_complete_iff_of_equivalence
category_theory.idempotents
src/category_theory/idempotents/basic.lean
[ "category_theory.abelian.basic" ]
[]
If `C` and `D` are equivalent categories, that `C` is idempotent complete iff `D` is.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_idempotent_complete_of_is_idempotent_complete_opposite (h : is_idempotent_complete Cᵒᵖ) : is_idempotent_complete C
begin refine ⟨_⟩, intros X p hp, rcases is_idempotent_complete.idempotents_split (op X) p.op (by rw [← op_comp, hp]) with ⟨Y, i, e, ⟨h₁, h₂⟩⟩, use [Y.unop, e.unop, i.unop], split, { simpa only [← unop_comp, h₁], }, { simpa only [← unop_comp, h₂], }, end
lemma
category_theory.idempotents.is_idempotent_complete_of_is_idempotent_complete_opposite
category_theory.idempotents
src/category_theory/idempotents/basic.lean
[ "category_theory.abelian.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_idempotent_complete_iff_opposite : is_idempotent_complete Cᵒᵖ ↔ is_idempotent_complete C
begin split, { exact is_idempotent_complete_of_is_idempotent_complete_opposite, }, { intro h, apply is_idempotent_complete_of_is_idempotent_complete_opposite, rw is_idempotent_complete_iff_of_equivalence (op_op_equivalence C), exact h, }, end
lemma
category_theory.idempotents.is_idempotent_complete_iff_opposite
category_theory.idempotents
src/category_theory/idempotents/basic.lean
[ "category_theory.abelian.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bicone [has_finite_biproducts C] {J : Type} [fintype J] (F : J → karoubi C) : bicone F
{ X := { X := biproduct (λ j, (F j).X), p := biproduct.map (λ j, (F j).p), idem := begin ext j, simp only [biproduct.ι_map_assoc, biproduct.ι_map], slice_lhs 1 2 { rw (F j).idem, }, end, }, π := λ j, { f := biproduct.map (λ j, (F j).p) ≫ bicone.π _ j, comm := by simp only [as...
def
category_theory.idempotents.karoubi.biproducts.bicone
category_theory.idempotents
src/category_theory/idempotents/biproducts.lean
[ "category_theory.idempotents.karoubi" ]
[ "comm", "fintype", "hom_ext" ]
The `bicone` used in order to obtain the existence of the biproduct of a functor `J ⥤ karoubi C` when the category `C` is additive.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
karoubi_has_finite_biproducts [has_finite_biproducts C] : has_finite_biproducts (karoubi C)
{ out := λ n, { has_biproduct := λ F, begin classical, apply has_biproduct_of_total (biproducts.bicone F), ext1, ext1, simp only [id_eq, comp_id, biproducts.bicone_X_p, biproduct.ι_map], rw [sum_hom, comp_sum, finset.sum_eq_single j], rotate, { intros j' h1 h2, simp only [b...
lemma
category_theory.idempotents.karoubi.karoubi_has_finite_biproducts
category_theory.idempotents
src/category_theory/idempotents/biproducts.lean
[ "category_theory.idempotents.karoubi" ]
[ "finset.mem_univ" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
complement (P : karoubi C) : karoubi C
{ X := P.X, p := 𝟙 _ - P.p, idem := idem_of_id_sub_idem P.p P.idem, }
def
category_theory.idempotents.karoubi.complement
category_theory.idempotents
src/category_theory/idempotents/biproducts.lean
[ "category_theory.idempotents.karoubi" ]
[]
`P.complement` is the formal direct factor of `P.X` given by the idempotent endomorphism `𝟙 P.X - P.p`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
decomposition (P : karoubi C) : P ⊞ P.complement ≅ (to_karoubi _).obj P.X
{ hom := biprod.desc P.decomp_id_i P.complement.decomp_id_i, inv := biprod.lift P.decomp_id_p P.complement.decomp_id_p, hom_inv_id' := begin ext1, { simp only [← assoc, biprod.inl_desc, comp_id, biprod.lift_eq, comp_add, ← decomp_id, id_comp, add_right_eq_self], convert zero_comp, ext, ...
def
category_theory.idempotents.karoubi.decomposition
category_theory.idempotents
src/category_theory/idempotents/biproducts.lean
[ "category_theory.idempotents.karoubi" ]
[]
A formal direct factor `P : karoubi C` of an object `P.X : C` in a preadditive category is actually a direct factor of the image `(to_karoubi C).obj P.X` of `P.X` in the category `karoubi C`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
app_idem : P.p.app X ≫ P.p.app X = P.p.app X
congr_app P.idem X
lemma
category_theory.idempotents.app_idem
category_theory.idempotents
src/category_theory/idempotents/functor_categories.lean
[ "category_theory.idempotents.karoubi" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
app_p_comp : P.p.app X ≫ f.f.app X = f.f.app X
congr_app (p_comp f) X
lemma
category_theory.idempotents.app_p_comp
category_theory.idempotents
src/category_theory/idempotents/functor_categories.lean
[ "category_theory.idempotents.karoubi" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
app_comp_p : f.f.app X ≫ Q.p.app X = f.f.app X
congr_app (comp_p f) X
lemma
category_theory.idempotents.app_comp_p
category_theory.idempotents
src/category_theory/idempotents/functor_categories.lean
[ "category_theory.idempotents.karoubi" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
app_p_comm : P.p.app X ≫ f.f.app X = f.f.app X ≫ Q.p.app X
congr_app (p_comm f) X
lemma
category_theory.idempotents.app_p_comm
category_theory.idempotents
src/category_theory/idempotents/functor_categories.lean
[ "category_theory.idempotents.karoubi" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
functor_category_is_idempotent_complete [is_idempotent_complete C] : is_idempotent_complete (J ⥤ C)
begin refine ⟨_⟩, intros F p hp, have hC := (is_idempotent_complete_iff_has_equalizer_of_id_and_idempotent C).mp infer_instance, haveI : ∀ (j : J), has_equalizer (𝟙 _) (p.app j) := λ j, hC _ _ (congr_app hp j), /- We construct the direct factor `Y` associated to `p : F ⟶ F` by computing the equalizer of ...
instance
category_theory.idempotents.functor_category_is_idempotent_complete
category_theory.idempotents
src/category_theory/idempotents/functor_categories.lean
[ "category_theory.idempotents.karoubi" ]
[ "functor.map_id" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
obj (P : karoubi (J ⥤ C)) : J ⥤ karoubi C
{ obj := λ j, ⟨P.X.obj j, P.p.app j, congr_app P.idem j⟩, map := λ j j' φ, { f := P.p.app j ≫ P.X.map φ, comm := begin simp only [nat_trans.naturality, assoc], have h := congr_app P.idem j, rw [nat_trans.comp_app] at h, slice_rhs 1 3 { erw [h, h], }, end }, }
def
category_theory.idempotents.karoubi_functor_category_embedding.obj
category_theory.idempotents
src/category_theory/idempotents/functor_categories.lean
[ "category_theory.idempotents.karoubi" ]
[ "comm" ]
On objects, the functor which sends a formal direct factor `P` of a functor `F : J ⥤ C` to the functor `J ⥤ karoubi C` which sends `(j : J)` to the corresponding direct factor of `F.obj j`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map {P Q : karoubi (J ⥤ C)} (f : P ⟶ Q) : obj P ⟶ obj Q
{ app := λ j, ⟨f.f.app j, congr_app f.comm j⟩, }
def
category_theory.idempotents.karoubi_functor_category_embedding.map
category_theory.idempotents
src/category_theory/idempotents/functor_categories.lean
[ "category_theory.idempotents.karoubi" ]
[]
Tautological action on maps of the functor `karoubi (J ⥤ C) ⥤ (J ⥤ karoubi C)`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
karoubi_functor_category_embedding : karoubi (J ⥤ C) ⥤ (J ⥤ karoubi C)
{ obj := karoubi_functor_category_embedding.obj, map := λ P Q, karoubi_functor_category_embedding.map, }
def
category_theory.idempotents.karoubi_functor_category_embedding
category_theory.idempotents
src/category_theory/idempotents/functor_categories.lean
[ "category_theory.idempotents.karoubi" ]
[]
The tautological fully faithful functor `karoubi (J ⥤ C) ⥤ (J ⥤ karoubi C)`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_karoubi_comp_karoubi_functor_category_embedding : (to_karoubi _) ⋙ karoubi_functor_category_embedding J C = (whiskering_right J _ _).obj (to_karoubi C)
begin apply functor.ext, { intros X Y f, ext j, dsimp [to_karoubi], simp only [eq_to_hom_app, eq_to_hom_refl, id_comp], erw [comp_id], }, { intro X, apply functor.ext, { intros j j' φ, ext, dsimp, simpa only [comp_id, id_comp], }, { intro j, refl, }, } end
lemma
category_theory.idempotents.to_karoubi_comp_karoubi_functor_category_embedding
category_theory.idempotents
src/category_theory/idempotents/functor_categories.lean
[ "category_theory.idempotents.karoubi" ]
[ "functor.ext" ]
The composition of `(J ⥤ C) ⥤ karoubi (J ⥤ C)` and `karoubi (J ⥤ C) ⥤ (J ⥤ karoubi C)` equals the functor `(J ⥤ C) ⥤ (J ⥤ karoubi C)` given by the composition with `to_karoubi C : C ⥤ karoubi C`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nat_trans_eq {F G : karoubi C ⥤ D} (φ : F ⟶ G) (P : karoubi C) : φ.app P = F.map (decomp_id_i P) ≫ φ.app P.X ≫ G.map (decomp_id_p P)
begin rw [← φ.naturality, ← assoc, ← F.map_comp], conv { to_lhs, rw [← id_comp (φ.app P), ← F.map_id], }, congr, apply decomp_id, end
lemma
category_theory.idempotents.nat_trans_eq
category_theory.idempotents
src/category_theory/idempotents/functor_extension.lean
[ "category_theory.idempotents.karoubi" ]
[]
A natural transformation between functors `karoubi C ⥤ D` is determined by its value on objects coming from `C`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
obj (F : C ⥤ karoubi D) : karoubi C ⥤ karoubi D
{ obj := λ P, ⟨(F.obj P.X).X, (F.map P.p).f, by simpa only [F.map_comp, hom_ext] using F.congr_map P.idem⟩, map := λ P Q f, ⟨(F.map f.f).f, by simpa only [F.map_comp, hom_ext] using F.congr_map f.comm⟩, }
def
category_theory.idempotents.functor_extension₁.obj
category_theory.idempotents
src/category_theory/idempotents/functor_extension.lean
[ "category_theory.idempotents.karoubi" ]
[ "hom_ext" ]
The canonical extension of a functor `C ⥤ karoubi D` to a functor `karoubi C ⥤ karoubi D`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map {F G : C ⥤ karoubi D} (φ : F ⟶ G) : obj F ⟶ obj G
{ app := λ P, { f := (F.map P.p).f ≫ (φ.app P.X).f, comm := begin have h := φ.naturality P.p, have h' := F.congr_map P.idem, simp only [hom_ext, karoubi.comp_f, F.map_comp] at h h', simp only [obj_obj_p, assoc, ← h], slice_rhs 1 3 { rw [h', h'], }, end, }, naturality' := λ P Q ...
def
category_theory.idempotents.functor_extension₁.map
category_theory.idempotents
src/category_theory/idempotents/functor_extension.lean
[ "category_theory.idempotents.karoubi" ]
[ "comm", "hom_ext" ]
Extension of a natural transformation `φ` between functors `C ⥤ karoubi D` to a natural transformation between the extension of these functors to `karoubi C ⥤ karoubi D`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
functor_extension₁ : (C ⥤ karoubi D) ⥤ (karoubi C ⥤ karoubi D)
{ obj := functor_extension₁.obj, map := λ F G, functor_extension₁.map, map_id' := λ F, by { ext P, exact comp_p (F.map P.p), }, map_comp' := λ F G H φ φ', begin ext P, simp only [comp_f, functor_extension₁.map_app_f, nat_trans.comp_app, assoc], have h := φ.naturality P.p, have h' := F.congr_map P....
def
category_theory.idempotents.functor_extension₁
category_theory.idempotents
src/category_theory/idempotents/functor_extension.lean
[ "category_theory.idempotents.karoubi" ]
[ "hom_ext" ]
The canonical functor `(C ⥤ karoubi D) ⥤ (karoubi C ⥤ karoubi D)`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
functor_extension₁_comp_whiskering_left_to_karoubi : functor_extension₁ C D ⋙ (whiskering_left C (karoubi C) (karoubi D)).obj (to_karoubi C) = 𝟭 _
begin refine functor.ext _ _, { intro F, refine functor.ext _ _, { intro X, ext, { dsimp, rw [id_comp, comp_id, F.map_id, id_eq], }, { refl, }, }, { intros X Y f, ext, dsimp, simp only [comp_id, eq_to_hom_f, eq_to_hom_refl, comp_p, functor_extension₁.obj_obj_p...
lemma
category_theory.idempotents.functor_extension₁_comp_whiskering_left_to_karoubi
category_theory.idempotents
src/category_theory/idempotents/functor_extension.lean
[ "category_theory.idempotents.karoubi" ]
[ "functor.ext", "functor.map_id" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
functor_extension₁_comp_whiskering_left_to_karoubi_iso : functor_extension₁ C D ⋙ (whiskering_left C (karoubi C) (karoubi D)).obj (to_karoubi C) ≅ 𝟭 _
eq_to_iso (functor_extension₁_comp_whiskering_left_to_karoubi C D)
def
category_theory.idempotents.functor_extension₁_comp_whiskering_left_to_karoubi_iso
category_theory.idempotents
src/category_theory/idempotents/functor_extension.lean
[ "category_theory.idempotents.karoubi" ]
[]
The natural isomorphism expressing that functors `karoubi C ⥤ karoubi D` obtained using `functor_extension₁` actually extends the original functors `C ⥤ karoubi D`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
karoubi_universal₁.counit_iso : (whiskering_left C (karoubi C) (karoubi D)).obj (to_karoubi C) ⋙ functor_extension₁ C D ≅ 𝟭 _
nat_iso.of_components (λ G, { hom := { app := λ P, { f := (G.map (decomp_id_p P)).f, comm := by simpa only [hom_ext, G.map_comp, G.map_id] using G.congr_map (show P.decomp_id_p = (to_karoubi C).map P.p ≫ P.decomp_id_p ≫ 𝟙 _, by simp), }, naturality' := λ P Q f, by simpa only...
def
category_theory.idempotents.karoubi_universal₁.counit_iso
category_theory.idempotents
src/category_theory/idempotents/functor_extension.lean
[ "category_theory.idempotents.karoubi" ]
[ "comm", "hom_ext" ]
The counit isomorphism of the equivalence `(C ⥤ karoubi D) ≌ (karoubi C ⥤ karoubi D)`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
karoubi_universal₁ : (C ⥤ karoubi D) ≌ (karoubi C ⥤ karoubi D)
{ functor := functor_extension₁ C D, inverse := (whiskering_left C (karoubi C) (karoubi D)).obj (to_karoubi C), unit_iso := (functor_extension₁_comp_whiskering_left_to_karoubi_iso C D).symm, counit_iso := karoubi_universal₁.counit_iso C D, functor_unit_iso_comp' := λ F, begin ext P, dsimp [functor_exten...
def
category_theory.idempotents.karoubi_universal₁
category_theory.idempotents
src/category_theory/idempotents/functor_extension.lean
[ "category_theory.idempotents.karoubi" ]
[ "hom_ext" ]
The equivalence of categories `(C ⥤ karoubi D) ≌ (karoubi C ⥤ karoubi D)`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
functor_extension₁_comp (F : C ⥤ karoubi D) (G : D ⥤ karoubi E) : (functor_extension₁ C E).obj (F ⋙ (functor_extension₁ D E).obj G) = (functor_extension₁ C D).obj F ⋙ (functor_extension₁ D E).obj G
functor.ext (by tidy) (λ X Y f, by { dsimp, simpa only [id_comp, comp_id], })
lemma
category_theory.idempotents.functor_extension₁_comp
category_theory.idempotents
src/category_theory/idempotents/functor_extension.lean
[ "category_theory.idempotents.karoubi" ]
[ "functor.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
functor_extension₂ : (C ⥤ D) ⥤ (karoubi C ⥤ karoubi D)
(whiskering_right C D (karoubi D)).obj (to_karoubi D) ⋙ functor_extension₁ C D
def
category_theory.idempotents.functor_extension₂
category_theory.idempotents
src/category_theory/idempotents/functor_extension.lean
[ "category_theory.idempotents.karoubi" ]
[]
The canonical functor `(C ⥤ D) ⥤ (karoubi C ⥤ karoubi D)`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
functor_extension₂_comp_whiskering_left_to_karoubi : functor_extension₂ C D ⋙ (whiskering_left C (karoubi C) (karoubi D)).obj (to_karoubi C) = (whiskering_right C D (karoubi D)).obj (to_karoubi D)
by simp only [functor_extension₂, functor.assoc, functor_extension₁_comp_whiskering_left_to_karoubi, functor.comp_id]
lemma
category_theory.idempotents.functor_extension₂_comp_whiskering_left_to_karoubi
category_theory.idempotents
src/category_theory/idempotents/functor_extension.lean
[ "category_theory.idempotents.karoubi" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
functor_extension₂_comp_whiskering_left_to_karoubi_iso : functor_extension₂ C D ⋙ (whiskering_left C (karoubi C) (karoubi D)).obj (to_karoubi C) ≅ (whiskering_right C D (karoubi D)).obj (to_karoubi D)
eq_to_iso (functor_extension₂_comp_whiskering_left_to_karoubi C D)
def
category_theory.idempotents.functor_extension₂_comp_whiskering_left_to_karoubi_iso
category_theory.idempotents
src/category_theory/idempotents/functor_extension.lean
[ "category_theory.idempotents.karoubi" ]
[]
The natural isomorphism expressing that functors `karoubi C ⥤ karoubi D` obtained using `functor_extension₂` actually extends the original functors `C ⥤ D`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
karoubi_universal₂ : (C ⥤ D) ≌ (karoubi C ⥤ karoubi D)
(equivalence.congr_right (to_karoubi D).as_equivalence).trans (karoubi_universal₁ C D)
def
category_theory.idempotents.karoubi_universal₂
category_theory.idempotents
src/category_theory/idempotents/functor_extension.lean
[ "category_theory.idempotents.karoubi" ]
[]
The equivalence of categories `(C ⥤ D) ≌ (karoubi C ⥤ karoubi D)` when `D` is idempotent complete.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
karoubi_universal₂_functor_eq : (karoubi_universal₂ C D).functor = functor_extension₂ C D
rfl
lemma
category_theory.idempotents.karoubi_universal₂_functor_eq
category_theory.idempotents
src/category_theory/idempotents/functor_extension.lean
[ "category_theory.idempotents.karoubi" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
functor_extension : (C ⥤ D) ⥤ (karoubi C ⥤ D)
functor_extension₂ C D ⋙ (whiskering_right (karoubi C) (karoubi D) D).obj (to_karoubi_is_equivalence D).inverse
def
category_theory.idempotents.functor_extension
category_theory.idempotents
src/category_theory/idempotents/functor_extension.lean
[ "category_theory.idempotents.karoubi" ]
[]
The extension of functors functor `(C ⥤ D) ⥤ (karoubi C ⥤ D)` when `D` is idempotent compltete.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
karoubi_universal : (C ⥤ D) ≌ (karoubi C ⥤ D)
(karoubi_universal₂ C D).trans (equivalence.congr_right (to_karoubi D).as_equivalence.symm)
def
category_theory.idempotents.karoubi_universal
category_theory.idempotents
src/category_theory/idempotents/functor_extension.lean
[ "category_theory.idempotents.karoubi" ]
[]
The equivalence `(C ⥤ D) ≌ (karoubi C ⥤ D)` when `D` is idempotent complete.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
karoubi_universal_functor_eq : (karoubi_universal C D).functor = functor_extension C D
rfl
lemma
category_theory.idempotents.karoubi_universal_functor_eq
category_theory.idempotents
src/category_theory/idempotents/functor_extension.lean
[ "category_theory.idempotents.karoubi" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
whiskering_left_obj_preimage_app {F G : karoubi C ⥤ D} (τ : to_karoubi _ ⋙ F ⟶ to_karoubi _ ⋙ G) (P : karoubi C) : (((whiskering_left _ _ _).obj (to_karoubi _)).preimage τ).app P = F.map P.decomp_id_i ≫ τ.app P.X ≫ G.map P.decomp_id_p
begin rw nat_trans_eq, congr' 2, exact congr_app (((whiskering_left _ _ _).obj (to_karoubi _)).image_preimage τ) P.X, end
lemma
category_theory.idempotents.whiskering_left_obj_preimage_app
category_theory.idempotents
src/category_theory/idempotents/functor_extension.lean
[ "category_theory.idempotents.karoubi" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
p_comp_d : P.p.f n ≫ f.f.f n = f.f.f n
homological_complex.congr_hom (p_comp f) n
lemma
category_theory.idempotents.karoubi.homological_complex.p_comp_d
category_theory.idempotents
src/category_theory/idempotents/homological_complex.lean
[ "algebra.homology.additive", "category_theory.idempotents.karoubi" ]
[ "homological_complex.congr_hom" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_p_d : f.f.f n ≫ Q.p.f n = f.f.f n
homological_complex.congr_hom (comp_p f) n
lemma
category_theory.idempotents.karoubi.homological_complex.comp_p_d
category_theory.idempotents
src/category_theory/idempotents/homological_complex.lean
[ "algebra.homology.additive", "category_theory.idempotents.karoubi" ]
[ "homological_complex.congr_hom" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
p_comm_f : P.p.f n ≫ f.f.f n = f.f.f n ≫ Q.p.f n
homological_complex.congr_hom (p_comm f) n
lemma
category_theory.idempotents.karoubi.homological_complex.p_comm_f
category_theory.idempotents
src/category_theory/idempotents/homological_complex.lean
[ "algebra.homology.additive", "category_theory.idempotents.karoubi" ]
[ "homological_complex.congr_hom" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
p_idem : P.p.f n ≫ P.p.f n = P.p.f n
homological_complex.congr_hom P.idem n
lemma
category_theory.idempotents.karoubi.homological_complex.p_idem
category_theory.idempotents
src/category_theory/idempotents/homological_complex.lean
[ "algebra.homology.additive", "category_theory.idempotents.karoubi" ]
[ "homological_complex.congr_hom" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
obj (P : karoubi (homological_complex C c)) : homological_complex (karoubi C) c
{ X := λ n, ⟨P.X.X n, P.p.f n, by simpa only [homological_complex.comp_f] using homological_complex.congr_hom P.idem n⟩, d := λ i j, { f := P.p.f i ≫ P.X.d i j, comm := by tidy, }, shape' := λ i j hij, by simp only [hom_eq_zero_iff, P.X.shape i j hij, limits.comp_zero], }
def
category_theory.idempotents.karoubi_homological_complex_equivalence.functor.obj
category_theory.idempotents
src/category_theory/idempotents/homological_complex.lean
[ "algebra.homology.additive", "category_theory.idempotents.karoubi" ]
[ "comm", "homological_complex", "homological_complex.comp_f", "homological_complex.congr_hom" ]
The functor `karoubi (homological_complex C c) ⥤ homological_complex (karoubi C) c`, on objects.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map {P Q : karoubi (homological_complex C c)} (f : P ⟶ Q) : obj P ⟶ obj Q
{ f:= λ n, { f:= f.f.f n, comm := by simp, }, }
def
category_theory.idempotents.karoubi_homological_complex_equivalence.functor.map
category_theory.idempotents
src/category_theory/idempotents/homological_complex.lean
[ "algebra.homology.additive", "category_theory.idempotents.karoubi" ]
[ "comm", "homological_complex" ]
The functor `karoubi (homological_complex C c) ⥤ homological_complex (karoubi C) c`, on morphisms.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
functor : karoubi (homological_complex C c) ⥤ homological_complex (karoubi C) c
{ obj := functor.obj, map := λ P Q f, functor.map f, }
def
category_theory.idempotents.karoubi_homological_complex_equivalence.functor
category_theory.idempotents
src/category_theory/idempotents/homological_complex.lean
[ "algebra.homology.additive", "category_theory.idempotents.karoubi" ]
[ "homological_complex" ]
The functor `karoubi (homological_complex C c) ⥤ homological_complex (karoubi C) c`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
obj (K : homological_complex (karoubi C) c) : karoubi (homological_complex C c)
{ X := { X := λ n, (K.X n).X, d := λ i j, (K.d i j).f, shape' := λ i j hij, hom_eq_zero_iff.mp (K.shape i j hij), d_comp_d' := λ i j k hij hjk, by { simpa only [comp_f] using hom_eq_zero_iff.mp (K.d_comp_d i j k), }, }, p := { f := λ n, (K.X n).p, comm' := by simp, }, idem := by tidy, ...
def
category_theory.idempotents.karoubi_homological_complex_equivalence.inverse.obj
category_theory.idempotents
src/category_theory/idempotents/homological_complex.lean
[ "algebra.homology.additive", "category_theory.idempotents.karoubi" ]
[ "homological_complex" ]
The functor `homological_complex (karoubi C) c ⥤ karoubi (homological_complex C c)`, on objects
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map {K L : homological_complex (karoubi C) c} (f : K ⟶ L) : obj K ⟶ obj L
{ f:= { f := λ n, (f.f n).f, comm' := λ i j hij, by simpa only [comp_f] using hom_ext.mp (f.comm' i j hij), }, comm := by tidy, }
def
category_theory.idempotents.karoubi_homological_complex_equivalence.inverse.map
category_theory.idempotents
src/category_theory/idempotents/homological_complex.lean
[ "algebra.homology.additive", "category_theory.idempotents.karoubi" ]
[ "comm", "homological_complex" ]
The functor `homological_complex (karoubi C) c ⥤ karoubi (homological_complex C c)`, on morphisms
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inverse : homological_complex (karoubi C) c ⥤ karoubi (homological_complex C c)
{ obj := inverse.obj, map := λ K L f, inverse.map f, }
def
category_theory.idempotents.karoubi_homological_complex_equivalence.inverse
category_theory.idempotents
src/category_theory/idempotents/homological_complex.lean
[ "algebra.homology.additive", "category_theory.idempotents.karoubi" ]
[ "homological_complex" ]
The functor `homological_complex (karoubi C) c ⥤ karoubi (homological_complex C c)`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
counit_iso : inverse ⋙ functor ≅ 𝟭 (homological_complex (karoubi C) c)
eq_to_iso (functor.ext (λ P, homological_complex.ext (by tidy) (by tidy)) (by tidy))
def
category_theory.idempotents.karoubi_homological_complex_equivalence.counit_iso
category_theory.idempotents
src/category_theory/idempotents/homological_complex.lean
[ "algebra.homology.additive", "category_theory.idempotents.karoubi" ]
[ "functor.ext", "homological_complex", "homological_complex.ext" ]
The counit isomorphism of the equivalence `karoubi (homological_complex C c) ≌ homological_complex (karoubi C) c`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unit_iso : 𝟭 (karoubi (homological_complex C c)) ≅ functor ⋙ inverse
{ hom := { app := λ P, { f := { f := λ n, P.p.f n, comm' := λ i j hij, begin dsimp, simp only [homological_complex.hom.comm, homological_complex.hom.comm_assoc, homological_complex.p_idem], end }, comm := by { ext n, dsimp, simp only [homological_complex...
def
category_theory.idempotents.karoubi_homological_complex_equivalence.unit_iso
category_theory.idempotents
src/category_theory/idempotents/homological_complex.lean
[ "algebra.homology.additive", "category_theory.idempotents.karoubi" ]
[ "comm", "homological_complex", "homological_complex.comp_f", "homological_complex.hom.comm" ]
The unit isomorphism of the equivalence `karoubi (homological_complex C c) ≌ homological_complex (karoubi C) c`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
karoubi_homological_complex_equivalence : karoubi (homological_complex C c) ≌ homological_complex (karoubi C) c
{ functor := karoubi_homological_complex_equivalence.functor, inverse := karoubi_homological_complex_equivalence.inverse, unit_iso := karoubi_homological_complex_equivalence.unit_iso, counit_iso := karoubi_homological_complex_equivalence.counit_iso, }
def
category_theory.idempotents.karoubi_homological_complex_equivalence
category_theory.idempotents
src/category_theory/idempotents/homological_complex.lean
[ "algebra.homology.additive", "category_theory.idempotents.karoubi" ]
[ "homological_complex" ]
The equivalence `karoubi (homological_complex C c) ≌ homological_complex (karoubi C) c`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
karoubi_chain_complex_equivalence : karoubi (chain_complex C α) ≌ chain_complex (karoubi C) α
karoubi_homological_complex_equivalence C (complex_shape.down α)
def
category_theory.idempotents.karoubi_chain_complex_equivalence
category_theory.idempotents
src/category_theory/idempotents/homological_complex.lean
[ "algebra.homology.additive", "category_theory.idempotents.karoubi" ]
[ "chain_complex", "complex_shape.down" ]
The equivalence `karoubi (chain_complex C α) ≌ chain_complex (karoubi C) α`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
karoubi_cochain_complex_equivalence : karoubi (cochain_complex C α) ≌ cochain_complex (karoubi C) α
karoubi_homological_complex_equivalence C (complex_shape.up α)
def
category_theory.idempotents.karoubi_cochain_complex_equivalence
category_theory.idempotents
src/category_theory/idempotents/homological_complex.lean
[ "algebra.homology.additive", "category_theory.idempotents.karoubi" ]
[ "cochain_complex", "complex_shape.up" ]
The equivalence `karoubi (cochain_complex C α) ≌ cochain_complex (karoubi C) α`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
karoubi
(X : C) (p : X ⟶ X) (idem : p ≫ p = p)
structure
category_theory.idempotents.karoubi
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[]
In a preadditive category `C`, when an object `X` decomposes as `X ≅ P ⨿ Q`, one may consider `P` as a direct factor of `X` and up to unique isomorphism, it is determined by the obvious idempotent `X ⟶ P ⟶ X` which is the projection onto `P` with kernel `Q`. More generally, one may define a formal direct factor of an o...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ext {P Q : karoubi C} (h_X : P.X = Q.X) (h_p : P.p ≫ eq_to_hom h_X = eq_to_hom h_X ≫ Q.p) : P = Q
begin cases P, cases Q, dsimp at h_X h_p, subst h_X, simpa only [true_and, eq_self_iff_true, id_comp, eq_to_hom_refl, heq_iff_eq, comp_id] using h_p, end
lemma
category_theory.idempotents.karoubi.ext
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[ "heq_iff_eq" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
hom (P Q : karoubi C)
(f : P.X ⟶ Q.X) (comm : f = P.p ≫ f ≫ Q.p)
structure
category_theory.idempotents.karoubi.hom
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[ "comm" ]
A morphism `P ⟶ Q` in the category `karoubi C` is a morphism in the underlying category `C` which satisfies a relation, which in the preadditive case, expresses that it induces a map between the corresponding "formal direct factors" and that it vanishes on the complement formal direct factor.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
hom_ext {P Q : karoubi C} {f g : hom P Q} : f = g ↔ f.f = g.f
begin split, { intro h, rw h, }, { ext, } end
lemma
category_theory.idempotents.karoubi.hom_ext
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[ "hom_ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
p_comp {P Q : karoubi C} (f : hom P Q) : P.p ≫ f.f = f.f
by rw [f.comm, ← assoc, P.idem]
lemma
category_theory.idempotents.karoubi.p_comp
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_p {P Q : karoubi C} (f : hom P Q) : f.f ≫ Q.p = f.f
by rw [f.comm, assoc, assoc, Q.idem]
lemma
category_theory.idempotents.karoubi.comp_p
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
p_comm {P Q : karoubi C} (f : hom P Q) : P.p ≫ f.f = f.f ≫ Q.p
by rw [p_comp, comp_p]
lemma
category_theory.idempotents.karoubi.p_comm
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_proof {P Q R : karoubi C} (g : hom Q R) (f : hom P Q) : f.f ≫ g.f = P.p ≫ (f.f ≫ g.f) ≫ R.p
by rw [assoc, comp_p, ← assoc, p_comp]
lemma
category_theory.idempotents.karoubi.comp_proof
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_f {P Q R : karoubi C} (f : P ⟶ Q) (g : Q ⟶ R) : (f ≫ g).f = f.f ≫ g.f
by refl
lemma
category_theory.idempotents.karoubi.comp_f
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
id_eq {P : karoubi C} : 𝟙 P = ⟨P.p, by repeat { rw P.idem, }⟩
by refl
lemma
category_theory.idempotents.karoubi.id_eq
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe : has_coe_t C (karoubi C)
⟨λ X, ⟨X, 𝟙 X, by rw comp_id⟩⟩
instance
category_theory.idempotents.karoubi.coe
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[]
It is possible to coerce an object of `C` into an object of `karoubi C`. See also the functor `to_karoubi`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_X (X : C) : (X : karoubi C).X = X
by refl
lemma
category_theory.idempotents.karoubi.coe_X
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_p (X : C) : (X : karoubi C).p = 𝟙 X
by refl
lemma
category_theory.idempotents.karoubi.coe_p
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_to_hom_f {P Q : karoubi C} (h : P = Q) : karoubi.hom.f (eq_to_hom h) = P.p ≫ eq_to_hom (congr_arg karoubi.X h)
by { subst h, simp only [eq_to_hom_refl, karoubi.id_eq, comp_id], }
lemma
category_theory.idempotents.karoubi.eq_to_hom_f
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_karoubi : C ⥤ karoubi C
{ obj := λ X, ⟨X, 𝟙 X, by rw comp_id⟩, map := λ X Y f, ⟨f, by simp only [comp_id, id_comp]⟩ }
def
category_theory.idempotents.to_karoubi
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[]
The obvious fully faithful functor `to_karoubi` sends an object `X : C` to the obvious formal direct factor of `X` given by `𝟙 X`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
hom_eq_zero_iff [preadditive C] {P Q : karoubi C} {f : hom P Q} : f = 0 ↔ f.f = 0
hom_ext
lemma
category_theory.idempotents.karoubi.hom_eq_zero_iff
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[ "hom_ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inclusion_hom [preadditive C] (P Q : karoubi C) : add_monoid_hom (P ⟶ Q) (P.X ⟶ Q.X)
{ to_fun := λ f, f.f, map_zero' := rfl, map_add' := λ f g, rfl }
def
category_theory.idempotents.karoubi.inclusion_hom
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[ "add_monoid_hom" ]
The map sending `f : P ⟶ Q` to `f.f : P.X ⟶ Q.X` is additive.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sum_hom [preadditive C] {P Q : karoubi C} {α : Type*} (s : finset α) (f : α → (P ⟶ Q)) : (∑ x in s, f x).f = ∑ x in s, (f x).f
add_monoid_hom.map_sum (inclusion_hom P Q) f s
lemma
category_theory.idempotents.karoubi.sum_hom
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[ "finset" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_karoubi_is_equivalence [is_idempotent_complete C] : is_equivalence (to_karoubi C)
equivalence.of_fully_faithfully_ess_surj (to_karoubi C)
def
category_theory.idempotents.to_karoubi_is_equivalence
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[]
If `C` is idempotent complete, the functor `to_karoubi : C ⥤ karoubi C` is an equivalence.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_karoubi_equivalence [is_idempotent_complete C] : C ≌ karoubi C
by { haveI := to_karoubi_is_equivalence C, exact functor.as_equivalence (to_karoubi C), }
def
category_theory.idempotents.to_karoubi_equivalence
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[]
The equivalence `C ≅ karoubi C` when `C` is idempotent complete.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_karoubi_equivalence_functor_additive [preadditive C] [is_idempotent_complete C] : (to_karoubi_equivalence C).functor.additive
(infer_instance : (to_karoubi C).additive)
instance
category_theory.idempotents.to_karoubi_equivalence_functor_additive
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[ "additive" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
decomp_id_i (P : karoubi C) : P ⟶ P.X
⟨P.p, by erw [coe_p, comp_id, P.idem]⟩
def
category_theory.idempotents.karoubi.decomp_id_i
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[]
The split mono which appears in the factorisation `decomp_id P`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
decomp_id_p (P : karoubi C) : (P.X : karoubi C) ⟶ P
⟨P.p, by erw [coe_p, id_comp, P.idem]⟩
def
category_theory.idempotents.karoubi.decomp_id_p
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[]
The split epi which appears in the factorisation `decomp_id P`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
decomp_id (P : karoubi C) : 𝟙 P = (decomp_id_i P) ≫ (decomp_id_p P)
by { ext, simp only [comp_f, id_eq, P.idem, decomp_id_i, decomp_id_p], }
lemma
category_theory.idempotents.karoubi.decomp_id
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[]
The formal direct factor of `P.X` given by the idempotent `P.p` in the category `C` is actually a direct factor in the category `karoubi C`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
decomp_p (P : karoubi C) : (to_karoubi C).map P.p = (decomp_id_p P) ≫ (decomp_id_i P)
by { ext, simp only [comp_f, decomp_id_p_f, decomp_id_i_f, P.idem, to_karoubi_map_f], }
lemma
category_theory.idempotents.karoubi.decomp_p
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
decomp_id_i_to_karoubi (X : C) : decomp_id_i ((to_karoubi C).obj X) = 𝟙 _
by { ext, refl, }
lemma
category_theory.idempotents.karoubi.decomp_id_i_to_karoubi
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
decomp_id_p_to_karoubi (X : C) : decomp_id_p ((to_karoubi C).obj X) = 𝟙 _
by { ext, refl, }
lemma
category_theory.idempotents.karoubi.decomp_id_p_to_karoubi
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
decomp_id_i_naturality {P Q : karoubi C} (f : P ⟶ Q) : f ≫ decomp_id_i _ = decomp_id_i _ ≫ ⟨f.f, by erw [comp_id, id_comp]⟩
by { ext, simp only [comp_f, decomp_id_i_f, karoubi.comp_p, karoubi.p_comp], }
lemma
category_theory.idempotents.karoubi.decomp_id_i_naturality
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
decomp_id_p_naturality {P Q : karoubi C} (f : P ⟶ Q) : decomp_id_p P ≫ f = (⟨f.f, by erw [comp_id, id_comp]⟩ : (P.X : karoubi C) ⟶ Q.X) ≫ decomp_id_p Q
by { ext, simp only [comp_f, decomp_id_p_f, karoubi.comp_p, karoubi.p_comp], }
lemma
category_theory.idempotents.karoubi.decomp_id_p_naturality
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
zsmul_hom [preadditive C] {P Q : karoubi C} (n : ℤ) (f : P ⟶ Q) : (n • f).f = n • f.f
map_zsmul (inclusion_hom P Q) n f
lemma
category_theory.idempotents.karoubi.zsmul_hom
category_theory.idempotents
src/category_theory/idempotents/karoubi.lean
[ "category_theory.idempotents.basic", "category_theory.preadditive.additive_functor", "category_theory.equivalence" ]
[ "map_zsmul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inverse : karoubi (karoubi C) ⥤ karoubi C
{ obj := λ P, ⟨P.X.X, P.p.f, by simpa only [hom_ext] using P.idem⟩, map := λ P Q f, ⟨f.f.f, by simpa only [hom_ext] using f.comm⟩, }
def
category_theory.idempotents.karoubi_karoubi.inverse
category_theory.idempotents
src/category_theory/idempotents/karoubi_karoubi.lean
[ "category_theory.idempotents.karoubi" ]
[ "hom_ext" ]
The canonical functor `karoubi (karoubi C) ⥤ karoubi C`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unit_iso : 𝟭 (karoubi C) ≅ to_karoubi (karoubi C) ⋙ inverse C
eq_to_iso (functor.ext (by tidy) (by tidy))
def
category_theory.idempotents.karoubi_karoubi.unit_iso
category_theory.idempotents
src/category_theory/idempotents/karoubi_karoubi.lean
[ "category_theory.idempotents.karoubi" ]
[ "functor.ext" ]
The unit isomorphism of the equivalence
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
counit_iso : inverse C ⋙ to_karoubi (karoubi C) ≅ 𝟭 (karoubi (karoubi C))
{ hom := { app := λ P, { f := { f := P.p.1, comm := begin have h := P.idem, simp only [hom_ext, comp_f] at h, erw [← assoc, h, comp_p], end, }, comm := begin have h := P.idem, simp only [hom_ext, comp_f] at h ⊢, erw [h, h], en...
def
category_theory.idempotents.karoubi_karoubi.counit_iso
category_theory.idempotents
src/category_theory/idempotents/karoubi_karoubi.lean
[ "category_theory.idempotents.karoubi" ]
[ "comm", "hom_ext" ]
The counit isomorphism of the equivalence
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equivalence : karoubi C ≌ karoubi (karoubi C)
{ functor := to_karoubi (karoubi C), inverse := karoubi_karoubi.inverse C, unit_iso := karoubi_karoubi.unit_iso C, counit_iso := karoubi_karoubi.counit_iso C, }
def
category_theory.idempotents.karoubi_karoubi.equivalence
category_theory.idempotents
src/category_theory/idempotents/karoubi_karoubi.lean
[ "category_theory.idempotents.karoubi" ]
[]
The equivalence `karoubi C ≌ karoubi (karoubi C)`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equivalence.additive_functor [preadditive C] : functor.additive (equivalence C).functor
by { dsimp, apply_instance, }
instance
category_theory.idempotents.karoubi_karoubi.equivalence.additive_functor
category_theory.idempotents
src/category_theory/idempotents/karoubi_karoubi.lean
[ "category_theory.idempotents.karoubi" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equivalence.additive_inverse [preadditive C] : functor.additive (equivalence C).inverse
by { dsimp, apply_instance, }
instance
category_theory.idempotents.karoubi_karoubi.equivalence.additive_inverse
category_theory.idempotents
src/category_theory/idempotents/karoubi_karoubi.lean
[ "category_theory.idempotents.karoubi" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
right_adjoint : comm_sq (adj.hom_equiv _ _ u) i (F.map p) (adj.hom_equiv _ _ v)
⟨begin simp only [adjunction.hom_equiv_unit, assoc, ← F.map_comp, sq.w], rw [F.map_comp, adjunction.unit_naturality_assoc], end⟩
lemma
category_theory.comm_sq.right_adjoint
category_theory.lifting_properties
src/category_theory/lifting_properties/adjunction.lean
[ "category_theory.lifting_properties.basic", "category_theory.adjunction.basic" ]
[]
When we have an adjunction `G ⊣ F`, any commutative square where the left map is of the form `G.map i` and the right map is `p` has an "adjoint" commutative square whose left map is `i` and whose right map is `F.map p`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
right_adjoint_lift_struct_equiv : sq.lift_struct ≃ (sq.right_adjoint adj).lift_struct
{ to_fun := λ l, { l := adj.hom_equiv _ _ l.l, fac_left' := by rw [← adj.hom_equiv_naturality_left, l.fac_left], fac_right' := by rw [← adjunction.hom_equiv_naturality_right, l.fac_right], }, inv_fun := λ l, { l := (adj.hom_equiv _ _).symm l.l, fac_left' := begin rw [← adjunction.hom_equiv_natur...
def
category_theory.comm_sq.right_adjoint_lift_struct_equiv
category_theory.lifting_properties
src/category_theory/lifting_properties/adjunction.lean
[ "category_theory.lifting_properties.basic", "category_theory.adjunction.basic" ]
[ "adj", "inv_fun" ]
The liftings of a commutative are in bijection with the liftings of its (right) adjoint square.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
right_adjoint_has_lift_iff : has_lift (sq.right_adjoint adj) ↔ has_lift sq
begin simp only [has_lift.iff], exact equiv.nonempty_congr (sq.right_adjoint_lift_struct_equiv adj).symm, end
lemma
category_theory.comm_sq.right_adjoint_has_lift_iff
category_theory.lifting_properties
src/category_theory/lifting_properties/adjunction.lean
[ "category_theory.lifting_properties.basic", "category_theory.adjunction.basic" ]
[ "adj", "equiv.nonempty_congr" ]
A square has a lifting if and only if its (right) adjoint square has a lifting.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
left_adjoint : comm_sq ((adj.hom_equiv _ _).symm u) (G.map i) p ((adj.hom_equiv _ _).symm v)
⟨begin simp only [adjunction.hom_equiv_counit, assoc, ← G.map_comp_assoc, ← sq.w], rw [G.map_comp, assoc, adjunction.counit_naturality], end⟩
lemma
category_theory.comm_sq.left_adjoint
category_theory.lifting_properties
src/category_theory/lifting_properties/adjunction.lean
[ "category_theory.lifting_properties.basic", "category_theory.adjunction.basic" ]
[]
When we have an adjunction `G ⊣ F`, any commutative square where the left map is of the form `i` and the right map is `F.map p` has an "adjoint" commutative square whose left map is `G.map i` and whose right map is `p`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83