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Mathlib.Algebra.Homology.TotalComplexSymmetry

The symmetry of the total complex of a bicomplex

Let K : HomologicalComplex₂ C c₁ c₂ be a bicomplex. If we assume both [TotalComplexShape c₁ c₂ c] and [TotalComplexShape c₂ c₁ c], we may form the total complex K.total c and K.flip.total c.

In this file, we show that if we assume [TotalComplexShapeSymmetry c₁ c₂ c], then there is an isomorphism K.totalFlipIso c : K.flip.total c ≅ K.total c.

Moreover, if we also have [TotalComplexShapeSymmetry c₂ c₁ c] and that the signs are compatible [TotalComplexShapeSymmetrySymmetry c₁ c₂ c], then the isomorphisms K.totalFlipIso c and K.flip.totalFlipIso c are inverse to each other.

Auxiliary definition for totalFlipIso.

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Instances For

    The symmetry isomorphism K.flip.total c ≅ K.total c of the total complex of a bicomplex when we have [TotalComplexShapeSymmetry c₁ c₂ c].

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    Instances For
      @[simp]
      theorem HomologicalComplex₂.ιTotal_totalFlipIso_f_hom {C : Type u_1} {I₁ : Type u_2} {I₂ : Type u_3} {J : Type u_4} [CategoryTheory.Category.{u_5, u_1} C] [CategoryTheory.Preadditive C] {c₁ : ComplexShape I₁} {c₂ : ComplexShape I₂} (K : HomologicalComplex₂ C c₁ c₂) (c : ComplexShape J) [TotalComplexShape c₁ c₂ c] [TotalComplexShape c₂ c₁ c] [TotalComplexShapeSymmetry c₁ c₂ c] [HomologicalComplex₂.HasTotal K c] [HomologicalComplex₂.HasTotal (HomologicalComplex₂.flip K) c] [DecidableEq J] (i₁ : I₁) (i₂ : I₂) (j : J) (h : ComplexShape.π c₂ c₁ c (i₂, i₁) = j) :
      @[simp]
      theorem HomologicalComplex₂.ιTotal_totalFlipIso_f_inv {C : Type u_1} {I₁ : Type u_2} {I₂ : Type u_3} {J : Type u_4} [CategoryTheory.Category.{u_5, u_1} C] [CategoryTheory.Preadditive C] {c₁ : ComplexShape I₁} {c₂ : ComplexShape I₂} (K : HomologicalComplex₂ C c₁ c₂) (c : ComplexShape J) [TotalComplexShape c₁ c₂ c] [TotalComplexShape c₂ c₁ c] [TotalComplexShapeSymmetry c₁ c₂ c] [HomologicalComplex₂.HasTotal K c] [HomologicalComplex₂.HasTotal (HomologicalComplex₂.flip K) c] [DecidableEq J] (i₁ : I₁) (i₂ : I₂) (j : J) (h : ComplexShape.π c₁ c₂ c (i₁, i₂) = j) :