Homology of preadditive categories #
In this file, it is shown that if C
is a preadditive category, then
ShortComplex C
is a preadditive category.
Equations
- CategoryTheory.ShortComplex.instAddCommGroupHom = AddCommGroup.mk ⋯
Equations
- CategoryTheory.ShortComplex.instPreadditive = { homGroup := inferInstance, add_comp := ⋯, comp_add := ⋯ }
Given a left homology map data for morphism φ
, this is the induced left homology
map data for -φ
.
Instances For
Given left homology map data for morphisms φ
and φ'
, this is
the induced left homology map data for φ + φ'
.
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Given a right homology map data for morphism φ
, this is the induced right homology
map data for -φ
.
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Given right homology map data for morphisms φ
and φ'
, this is the induced
right homology map data for φ + φ'
.
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Given a homology map data for a morphism φ
, this is the induced homology
map data for -φ
.
Equations
- γ.neg = { left := γ.left.neg, right := γ.right.neg }
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Given homology map data for morphisms φ
and φ'
, this is the induced homology
map data for φ + φ'
.
Equations
- γ.add γ' = { left := γ.left.add γ'.left, right := γ.right.add γ'.right }
Instances For
A homotopy between two morphisms of short complexes S₁ ⟶ S₂
consists of various
maps and conditions which will be sufficient to show that they induce the same morphism
in homology.
- h₀ : S₁.X₁ ⟶ S₂.X₁
a morphism
S₁.X₁ ⟶ S₂.X₁
- h₀_f : CategoryTheory.CategoryStruct.comp self.h₀ S₂.f = 0
- h₁ : S₁.X₂ ⟶ S₂.X₁
a morphism
S₁.X₂ ⟶ S₂.X₁
- h₂ : S₁.X₃ ⟶ S₂.X₂
a morphism
S₁.X₃ ⟶ S₂.X₂
- h₃ : S₁.X₃ ⟶ S₂.X₃
a morphism
S₁.X₃ ⟶ S₂.X₃
- g_h₃ : CategoryTheory.CategoryStruct.comp S₁.g self.h₃ = 0
- comm₁ : φ₁.τ₁ = CategoryTheory.CategoryStruct.comp S₁.f self.h₁ + self.h₀ + φ₂.τ₁
- comm₂ : φ₁.τ₂ = CategoryTheory.CategoryStruct.comp S₁.g self.h₂ + CategoryTheory.CategoryStruct.comp self.h₁ S₂.f + φ₂.τ₂
- comm₃ : φ₁.τ₃ = self.h₃ + CategoryTheory.CategoryStruct.comp self.h₂ S₂.g + φ₂.τ₃
Instances For
Constructor for null homotopic morphisms, see also Homotopy.ofNullHomotopic
and Homotopy.eq_add_nullHomotopic
.
Equations
- One or more equations did not get rendered due to their size.
Instances For
The obvious homotopy between two equal morphisms of short complexes.
Equations
- CategoryTheory.ShortComplex.Homotopy.ofEq h = { h₀ := 0, h₀_f := ⋯, h₁ := 0, h₂ := 0, h₃ := 0, g_h₃ := ⋯, comm₁ := ⋯, comm₂ := ⋯, comm₃ := ⋯ }
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The obvious homotopy between a morphism of short complexes and itself.
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The symmetry of homotopy between morphisms of short complexes.
Equations
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If two maps of short complexes are homotopic, their opposites also are.
Equations
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The transitivity of homotopy between morphisms of short complexes.
Equations
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Homotopy between morphisms of short complexes is compatible with addition.
Equations
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Homotopy between morphisms of short complexes is compatible with subtraction.
Equations
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Homotopy between morphisms of short complexes is compatible with precomposition.
Equations
- One or more equations did not get rendered due to their size.
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Homotopy between morphisms of short complexes is compatible with postcomposition.
Equations
- One or more equations did not get rendered due to their size.
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Homotopy between morphisms of short complexes is compatible with composition.
Equations
- h.comp h' = (h.compRight ψ₁).trans (h'.compLeft φ₂)
Instances For
The homotopy between morphisms in ShortComplex Cᵒᵖ
that is induced by a homotopy
between morphisms in ShortComplex C
.
Equations
- h.op = { h₀ := h.h₃.op, h₀_f := ⋯, h₁ := h.h₂.op, h₂ := h.h₁.op, h₃ := h.h₀.op, g_h₃ := ⋯, comm₁ := ⋯, comm₂ := ⋯, comm₃ := ⋯ }
Instances For
The homotopy between morphisms in ShortComplex C
that is induced by a homotopy
between morphisms in ShortComplex Cᵒᵖ
.
Equations
- h.unop = { h₀ := h.h₃.unop, h₀_f := ⋯, h₁ := h.h₂.unop, h₂ := h.h₁.unop, h₃ := h.h₀.unop, g_h₃ := ⋯, comm₁ := ⋯, comm₂ := ⋯, comm₃ := ⋯ }
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Equivalence expressing that two morphisms are homotopic iff their difference is homotopic to zero.
Equations
- One or more equations did not get rendered due to their size.
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A morphism constructed with nullHomotopic
is homotopic to zero.
Equations
- CategoryTheory.ShortComplex.Homotopy.ofNullHomotopic S₁ S₂ h₀ h₀_f h₁ h₂ h₃ g_h₃ = { h₀ := h₀, h₀_f := h₀_f, h₁ := h₁, h₂ := h₂, h₃ := h₃, g_h₃ := g_h₃, comm₁ := ⋯, comm₂ := ⋯, comm₃ := ⋯ }
Instances For
The left homology map data expressing that null homotopic maps induce the zero morphism in left homology.
Equations
- One or more equations did not get rendered due to their size.
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The right homology map data expressing that null homotopic maps induce the zero morphism in right homology.
Equations
- One or more equations did not get rendered due to their size.
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An homotopy equivalence between two short complexes S₁
and S₂
consists
of morphisms hom : S₁ ⟶ S₂
and inv : S₂ ⟶ S₁
such that both compositions
hom ≫ inv
and inv ≫ hom
are homotopic to the identity.
- hom : S₁ ⟶ S₂
the forward direction of a homotopy equivalence.
- inv : S₂ ⟶ S₁
the backwards direction of a homotopy equivalence.
- homotopyHomInvId : CategoryTheory.ShortComplex.Homotopy (CategoryTheory.CategoryStruct.comp self.hom self.inv) (CategoryTheory.CategoryStruct.id S₁)
the composition of the two directions of a homotopy equivalence is homotopic to the identity of the source
- homotopyInvHomId : CategoryTheory.ShortComplex.Homotopy (CategoryTheory.CategoryStruct.comp self.inv self.hom) (CategoryTheory.CategoryStruct.id S₂)
the composition of the two directions of a homotopy equivalence is homotopic to the identity of the target
Instances For
The homotopy equivalence from a short complex to itself that is induced by the identity.
Equations
- One or more equations did not get rendered due to their size.
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The inverse of a homotopy equivalence.
Equations
- e.symm = { hom := e.inv, inv := e.hom, homotopyHomInvId := e.homotopyInvHomId, homotopyInvHomId := e.homotopyHomInvId }
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The composition of homotopy equivalences.
Equations
- One or more equations did not get rendered due to their size.