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Mathlib.Algebra.Homology.ShortComplex.Basic

Short complexes #

This file defines the category ShortComplex C of diagrams X₁X₂X₃ such that the composition is zero.

Note: This structure ShortComplex C was first introduced in the Liquid Tensor Experiment.

A short complex in a category C with zero morphisms is the datum of two composable morphisms f : X₁X₂ and g : X₂X₃ such that fg = 0.

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    Morphisms of short complexes are the commutative diagrams of the obvious shape.

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      theorem CategoryTheory.ShortComplex.Hom.ext_iff {C : Type u_1} {inst✝ : Category.{u_3, u_1} C} {inst✝¹ : Limits.HasZeroMorphisms C} {S₁ S₂ : ShortComplex C} {x y : S₁.Hom S₂} :
      theorem CategoryTheory.ShortComplex.Hom.ext {C : Type u_1} {inst✝ : Category.{u_3, u_1} C} {inst✝¹ : Limits.HasZeroMorphisms C} {S₁ S₂ : ShortComplex C} {x y : S₁.Hom S₂} (τ₁ : x.τ₁ = y.τ₁) (τ₂ : x.τ₂ = y.τ₂) (τ₃ : x.τ₃ = y.τ₃) :
      x = y

      The identity morphism of a short complex.

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          def CategoryTheory.ShortComplex.Hom.comp {C : Type u_1} [Category.{u_3, u_1} C] [Limits.HasZeroMorphisms C] {S₁ S₂ S₃ : ShortComplex C} (φ₁₂ : S₁.Hom S₂) (φ₂₃ : S₂.Hom S₃) :
          S₁.Hom S₃

          The composition of morphisms of short complexes.

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              theorem CategoryTheory.ShortComplex.Hom.comp_τ₁ {C : Type u_1} [Category.{u_3, u_1} C] [Limits.HasZeroMorphisms C] {S₁ S₂ S₃ : ShortComplex C} (φ₁₂ : S₁.Hom S₂) (φ₂₃ : S₂.Hom S₃) :
              (φ₁₂.comp φ₂₃).τ₁ = CategoryStruct.comp φ₁₂.τ₁ φ₂₃.τ₁
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              theorem CategoryTheory.ShortComplex.Hom.comp_τ₂ {C : Type u_1} [Category.{u_3, u_1} C] [Limits.HasZeroMorphisms C] {S₁ S₂ S₃ : ShortComplex C} (φ₁₂ : S₁.Hom S₂) (φ₂₃ : S₂.Hom S₃) :
              (φ₁₂.comp φ₂₃).τ₂ = CategoryStruct.comp φ₁₂.τ₂ φ₂₃.τ₂
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              theorem CategoryTheory.ShortComplex.Hom.comp_τ₃ {C : Type u_1} [Category.{u_3, u_1} C] [Limits.HasZeroMorphisms C] {S₁ S₂ S₃ : ShortComplex C} (φ₁₂ : S₁.Hom S₂) (φ₂₃ : S₂.Hom S₃) :
              (φ₁₂.comp φ₂₃).τ₃ = CategoryStruct.comp φ₁₂.τ₃ φ₂₃.τ₃
              theorem CategoryTheory.ShortComplex.hom_ext {C : Type u_1} [Category.{u_3, u_1} C] [Limits.HasZeroMorphisms C] {S₁ S₂ : ShortComplex C} (f g : S₁ S₂) (h₁ : f.τ₁ = g.τ₁) (h₂ : f.τ₂ = g.τ₂) (h₃ : f.τ₃ = g.τ₃) :
              f = g
              def CategoryTheory.ShortComplex.homMk {C : Type u_1} [Category.{u_3, u_1} C] [Limits.HasZeroMorphisms C] {S₁ S₂ : ShortComplex C} (τ₁ : S₁.X₁ S₂.X₁) (τ₂ : S₁.X₂ S₂.X₂) (τ₃ : S₁.X₃ S₂.X₃) (comm₁₂ : CategoryStruct.comp τ₁ S₂.f = CategoryStruct.comp S₁.f τ₂) (comm₂₃ : CategoryStruct.comp τ₂ S₂.g = CategoryStruct.comp S₁.g τ₃) :
              S₁ S₂

              A constructor for morphisms in ShortComplex C when the commutativity conditions are not obvious.

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                  theorem CategoryTheory.ShortComplex.homMk_τ₂ {C : Type u_1} [Category.{u_3, u_1} C] [Limits.HasZeroMorphisms C] {S₁ S₂ : ShortComplex C} (τ₁ : S₁.X₁ S₂.X₁) (τ₂ : S₁.X₂ S₂.X₂) (τ₃ : S₁.X₃ S₂.X₃) (comm₁₂ : CategoryStruct.comp τ₁ S₂.f = CategoryStruct.comp S₁.f τ₂) (comm₂₃ : CategoryStruct.comp τ₂ S₂.g = CategoryStruct.comp S₁.g τ₃) :
                  (homMk τ₁ τ₂ τ₃ comm₁₂ comm₂₃).τ₂ = τ₂
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                  theorem CategoryTheory.ShortComplex.homMk_τ₁ {C : Type u_1} [Category.{u_3, u_1} C] [Limits.HasZeroMorphisms C] {S₁ S₂ : ShortComplex C} (τ₁ : S₁.X₁ S₂.X₁) (τ₂ : S₁.X₂ S₂.X₂) (τ₃ : S₁.X₃ S₂.X₃) (comm₁₂ : CategoryStruct.comp τ₁ S₂.f = CategoryStruct.comp S₁.f τ₂) (comm₂₃ : CategoryStruct.comp τ₂ S₂.g = CategoryStruct.comp S₁.g τ₃) :
                  (homMk τ₁ τ₂ τ₃ comm₁₂ comm₂₃).τ₁ = τ₁
                  @[simp]
                  theorem CategoryTheory.ShortComplex.homMk_τ₃ {C : Type u_1} [Category.{u_3, u_1} C] [Limits.HasZeroMorphisms C] {S₁ S₂ : ShortComplex C} (τ₁ : S₁.X₁ S₂.X₁) (τ₂ : S₁.X₂ S₂.X₂) (τ₃ : S₁.X₃ S₂.X₃) (comm₁₂ : CategoryStruct.comp τ₁ S₂.f = CategoryStruct.comp S₁.f τ₂) (comm₂₃ : CategoryStruct.comp τ₂ S₂.g = CategoryStruct.comp S₁.g τ₃) :
                  (homMk τ₁ τ₂ τ₃ comm₁₂ comm₂₃).τ₃ = τ₃
                  @[simp]
                  theorem CategoryTheory.ShortComplex.comp_τ₁ {C : Type u_1} [Category.{u_3, u_1} C] [Limits.HasZeroMorphisms C] {S₁ S₂ S₃ : ShortComplex C} (φ₁₂ : S₁ S₂) (φ₂₃ : S₂ S₃) :
                  (CategoryStruct.comp φ₁₂ φ₂₃).τ₁ = CategoryStruct.comp φ₁₂.τ₁ φ₂₃.τ₁
                  theorem CategoryTheory.ShortComplex.comp_τ₁_assoc {C : Type u_1} [Category.{u_3, u_1} C] [Limits.HasZeroMorphisms C] {S₁ S₂ S₃ : ShortComplex C} (φ₁₂ : S₁ S₂) (φ₂₃ : S₂ S₃) {Z : C} (h : S₃.X₁ Z) :
                  @[simp]
                  theorem CategoryTheory.ShortComplex.comp_τ₂ {C : Type u_1} [Category.{u_3, u_1} C] [Limits.HasZeroMorphisms C] {S₁ S₂ S₃ : ShortComplex C} (φ₁₂ : S₁ S₂) (φ₂₃ : S₂ S₃) :
                  (CategoryStruct.comp φ₁₂ φ₂₃).τ₂ = CategoryStruct.comp φ₁₂.τ₂ φ₂₃.τ₂
                  theorem CategoryTheory.ShortComplex.comp_τ₂_assoc {C : Type u_1} [Category.{u_3, u_1} C] [Limits.HasZeroMorphisms C] {S₁ S₂ S₃ : ShortComplex C} (φ₁₂ : S₁ S₂) (φ₂₃ : S₂ S₃) {Z : C} (h : S₃.X₂ Z) :
                  @[simp]
                  theorem CategoryTheory.ShortComplex.comp_τ₃ {C : Type u_1} [Category.{u_3, u_1} C] [Limits.HasZeroMorphisms C] {S₁ S₂ S₃ : ShortComplex C} (φ₁₂ : S₁ S₂) (φ₂₃ : S₂ S₃) :
                  (CategoryStruct.comp φ₁₂ φ₂₃).τ₃ = CategoryStruct.comp φ₁₂.τ₃ φ₂₃.τ₃
                  theorem CategoryTheory.ShortComplex.comp_τ₃_assoc {C : Type u_1} [Category.{u_3, u_1} C] [Limits.HasZeroMorphisms C] {S₁ S₂ S₃ : ShortComplex C} (φ₁₂ : S₁ S₂) (φ₂₃ : S₂ S₃) {Z : C} (h : S₃.X₃ Z) :

                  The first projection functor ShortComplex C ⥤ C.

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                      The second projection functor ShortComplex C ⥤ C.

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                          The third projection functor ShortComplex C ⥤ C.

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                              The natural transformation π₁π₂ induced by S.f for all S : ShortComplex C.

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                                  The natural transformation π₂π₃ induced by S.g for all S : ShortComplex C.

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                                      The short complex in D obtained by applying a functor F : C ⥤ D to a short complex in C, assuming that F preserves zero morphisms.

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                                          The morphism of short complexes S.map F ⟶ S.map G induced by a natural transformation F ⟶ G.

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                                              The isomorphism of short complexes S.map F ≅ S.map G induced by a natural isomorphism F ≅ G.

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                                                  The functor ShortComplex C ⥤ ShortComplex D induced by a functor C ⥤ D which preserves zero morphisms.

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                                                      def CategoryTheory.ShortComplex.isoMk {C : Type u_1} [Category.{u_3, u_1} C] [Limits.HasZeroMorphisms C] {S₁ S₂ : ShortComplex C} (e₁ : S₁.X₁ S₂.X₁) (e₂ : S₁.X₂ S₂.X₂) (e₃ : S₁.X₃ S₂.X₃) (comm₁₂ : CategoryStruct.comp e₁.hom S₂.f = CategoryStruct.comp S₁.f e₂.hom := by cat_disch) (comm₂₃ : CategoryStruct.comp e₂.hom S₂.g = CategoryStruct.comp S₁.g e₃.hom := by cat_disch) :
                                                      S₁ S₂

                                                      A constructor for isomorphisms in the category ShortComplex C

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                                                          theorem CategoryTheory.ShortComplex.isoMk_hom_τ₃ {C : Type u_1} [Category.{u_3, u_1} C] [Limits.HasZeroMorphisms C] {S₁ S₂ : ShortComplex C} (e₁ : S₁.X₁ S₂.X₁) (e₂ : S₁.X₂ S₂.X₂) (e₃ : S₁.X₃ S₂.X₃) (comm₁₂ : CategoryStruct.comp e₁.hom S₂.f = CategoryStruct.comp S₁.f e₂.hom := by cat_disch) (comm₂₃ : CategoryStruct.comp e₂.hom S₂.g = CategoryStruct.comp S₁.g e₃.hom := by cat_disch) :
                                                          (isoMk e₁ e₂ e₃ comm₁₂ comm₂₃).hom.τ₃ = e₃.hom
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                                                          theorem CategoryTheory.ShortComplex.isoMk_inv {C : Type u_1} [Category.{u_3, u_1} C] [Limits.HasZeroMorphisms C] {S₁ S₂ : ShortComplex C} (e₁ : S₁.X₁ S₂.X₁) (e₂ : S₁.X₂ S₂.X₂) (e₃ : S₁.X₃ S₂.X₃) (comm₁₂ : CategoryStruct.comp e₁.hom S₂.f = CategoryStruct.comp S₁.f e₂.hom := by cat_disch) (comm₂₃ : CategoryStruct.comp e₂.hom S₂.g = CategoryStruct.comp S₁.g e₃.hom := by cat_disch) :
                                                          (isoMk e₁ e₂ e₃ comm₁₂ comm₂₃).inv = homMk e₁.inv e₂.inv e₃.inv
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                                                          theorem CategoryTheory.ShortComplex.isoMk_hom_τ₂ {C : Type u_1} [Category.{u_3, u_1} C] [Limits.HasZeroMorphisms C] {S₁ S₂ : ShortComplex C} (e₁ : S₁.X₁ S₂.X₁) (e₂ : S₁.X₂ S₂.X₂) (e₃ : S₁.X₃ S₂.X₃) (comm₁₂ : CategoryStruct.comp e₁.hom S₂.f = CategoryStruct.comp S₁.f e₂.hom := by cat_disch) (comm₂₃ : CategoryStruct.comp e₂.hom S₂.g = CategoryStruct.comp S₁.g e₃.hom := by cat_disch) :
                                                          (isoMk e₁ e₂ e₃ comm₁₂ comm₂₃).hom.τ₂ = e₂.hom
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                                                          theorem CategoryTheory.ShortComplex.isoMk_hom_τ₁ {C : Type u_1} [Category.{u_3, u_1} C] [Limits.HasZeroMorphisms C] {S₁ S₂ : ShortComplex C} (e₁ : S₁.X₁ S₂.X₁) (e₂ : S₁.X₂ S₂.X₂) (e₃ : S₁.X₃ S₂.X₃) (comm₁₂ : CategoryStruct.comp e₁.hom S₂.f = CategoryStruct.comp S₁.f e₂.hom := by cat_disch) (comm₂₃ : CategoryStruct.comp e₂.hom S₂.g = CategoryStruct.comp S₁.g e₃.hom := by cat_disch) :
                                                          (isoMk e₁ e₂ e₃ comm₁₂ comm₂₃).hom.τ₁ = e₁.hom

                                                          The opposite ShortComplex in Cᵒᵖ associated to a short complex in C.

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                                                              def CategoryTheory.ShortComplex.opMap {C : Type u_1} [Category.{u_3, u_1} C] [Limits.HasZeroMorphisms C] {S₁ S₂ : ShortComplex C} (φ : S₁ S₂) :
                                                              S₂.op S₁.op

                                                              The opposite morphism in ShortComplex Cᵒᵖ associated to a morphism in ShortComplex C

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                                                                  The ShortComplex in C associated to a short complex in Cᵒᵖ.

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                                                                      The morphism in ShortComplex C associated to a morphism in ShortComplex Cᵒᵖ

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                                                                          The obvious functor (ShortComplex C)ᵒᵖ ⥤ ShortComplex Cᵒᵖ.

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                                                                              The obvious functor ShortComplex Cᵒᵖ ⥤ (ShortComplex C)ᵒᵖ.

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                                                                                  The obvious equivalence of categories (ShortComplex C)ᵒᵖ ≌ ShortComplex Cᵒᵖ.

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                                                                                      The canonical isomorphism S.unop.op ≅ S for a short complex S in Cᵒᵖ

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                                                                                          The canonical isomorphism S.op.unop ≅ S for a short complex S

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