Signs in constructions on homological complexes
In this file, we shall introduce various typeclasses which will allow the construction of the total complex of a bicomplex and of the the monoidal category structure on categories of homological complexes (TODO).
The most important definition is that of TotalComplexShape c₁ c₂ c₁₂
given
three complex shapes c₁
, c₂
, c₁₂
: it allows the definition of a total
complex functor HomologicalComplex₂ C c₁ c₂ ⥤ HomologicalComplex C c₁₂
(at least
when suitable coproducts exist).
In particular, we construct an instance of TotalComplexShape c c c
when c : ComplexShape I
and I
is an additive monoid equipped with a group homomorphism ε' : Multiplicative I → ℤˣ
satisfying certain properties (see ComplexShape.TensorSigns
).
A total complex shape for three complexes shapes c₁
, c₂
, c₁₂
on three types
I₁
, I₂
and I₁₂
consists of the data and properties that will allow the construction
of a total complex functor HomologicalComplex₂ C c₁ c₂ ⥤ HomologicalComplex C c₁₂
which
sends K
to a complex which in degree i₁₂ : I₁₂
consists of the coproduct
of the (K.X i₁).X i₂
such that π ⟨i₁, i₂⟩ = i₁₂
.
- π : I₁ × I₂ → I₁₂
a map on indices
the sign of the horizontal differential in the total complex
the sign of the vertical differential in the total complex
- rel₁ : ∀ {i₁ i₁' : I₁}, c₁.Rel i₁ i₁' → ∀ (i₂ : I₂), c₁₂.Rel (TotalComplexShape.π c₁ c₂ c₁₂ (i₁, i₂)) (TotalComplexShape.π c₁ c₂ c₁₂ (i₁', i₂))
- rel₂ : ∀ (i₁ : I₁) {i₂ i₂' : I₂}, c₂.Rel i₂ i₂' → c₁₂.Rel (TotalComplexShape.π c₁ c₂ c₁₂ (i₁, i₂)) (TotalComplexShape.π c₁ c₂ c₁₂ (i₁, i₂'))
- ε₂_ε₁ : ∀ {i₁ i₁' : I₁} {i₂ i₂' : I₂}, c₁.Rel i₁ i₁' → c₂.Rel i₂ i₂' → TotalComplexShape.ε₂ c₁ c₂ c₁₂ (i₁, i₂) * TotalComplexShape.ε₁ c₁ c₂ c₁₂ (i₁, i₂') = -TotalComplexShape.ε₁ c₁ c₂ c₁₂ (i₁, i₂) * TotalComplexShape.ε₂ c₁ c₂ c₁₂ (i₁', i₂)
Instances
The map I₁ × I₂ → I₁₂
on indices given by TotalComplexShape c₁ c₂ c₁₂
.
Equations
- c₁.π c₂ c₁₂ i = TotalComplexShape.π c₁ c₂ c₁₂ i
Instances For
The sign of the horizontal differential in the total complex.
Equations
- c₁.ε₁ c₂ c₁₂ i = TotalComplexShape.ε₁ c₁ c₂ c₁₂ i
Instances For
The sign of the vertical differential in the total complex.
Equations
- c₁.ε₂ c₂ c₁₂ i = TotalComplexShape.ε₂ c₁ c₂ c₁₂ i
Instances For
If I
is an additive monoid and c : ComplexShape I
, c.TensorSigns
contains the data of
map ε : I → ℤˣ
and properties which allows the construction of a TotalComplexShape c c c
.
- ε' : Multiplicative I →* ℤˣ
the signs which appear in the vertical differential of the total complex
- ε'_succ : ∀ (p q : I), c.Rel p q → (ComplexShape.TensorSigns.ε' c) q = -(ComplexShape.TensorSigns.ε' c) p
Instances
The signs which appear in the vertical differential of the total complex.
Equations
- c.ε i = (ComplexShape.TensorSigns.ε' c) i
Instances For
Equations
- One or more equations did not get rendered due to their size.
Equations
- One or more equations did not get rendered due to their size.
Equations
- One or more equations did not get rendered due to their size.
When we have six complex shapes c₁
, c₂
, c₃
, c₁₂
, c₂₃
, c
, and total functors
HomologicalComplex₂ C c₁ c₂ ⥤ HomologicalComplex C c₁₂
,
HomologicalComplex₂ C c₁₂ c₃ ⥤ HomologicalComplex C c
,
HomologicalComplex₂ C c₂ c₃ ⥤ HomologicalComplex C c₂₃
,
HomologicalComplex₂ C c₁ c₂₂₃ ⥤ HomologicalComplex C c
, we get two ways to
compute the total complex of a triple complex in HomologicalComplex₃ C c₁ c₂ c₃
, then
under this assumption [Associative c₁ c₂ c₃ c₁₂ c₂₃ c]
, these two complexes
canonically identify (without introducing signs).
- assoc : ∀ (i₁ : I₁) (i₂ : I₂) (i₃ : I₃), c₁₂.π c₃ c (c₁.π c₂ c₁₂ (i₁, i₂), i₃) = c₁.π c₂₃ c (i₁, c₂.π c₃ c₂₃ (i₂, i₃))
Instances
The map I₁ × I₂ × I₃ → j
that is obtained using TotalComplexShape c₁ c₂ c₁₂
and TotalComplexShape c₁₂ c₃ c
when c₁ : ComplexShape I₁
, c₂ : ComplexShape I₂
,
c₃ : ComplexShape I₃
, c₁₂ : ComplexShape I₁₂
and c : ComplexShape J
.
Equations
- c₁.r c₂ c₃ c₁₂ c (i₁, i₂, i₃) = c₁₂.π c₃ c (c₁.π c₂ c₁₂ (i₁, i₂), i₃)
Instances For
The GradedObject.BifunctorComp₁₂IndexData
which arises from complex shapes.
Equations
- c₁.ρ₁₂ c₂ c₃ c₁₂ c = { I₁₂ := I₁₂, p := c₁.π c₂ c₁₂, q := c₁₂.π c₃ c, hpq := ⋯ }
Instances For
The GradedObject.BifunctorComp₂₃IndexData
which arises from complex shapes.
Equations
- c₁.ρ₂₃ c₂ c₃ c₁₂ c₂₃ c = { I₂₃ := I₂₃, p := c₂.π c₃ c₂₃, q := c₁.π c₂₃ c, hpq := ⋯ }
Instances For
Equations
- ⋯ = ⋯
A total complex shape symmetry contains the data and properties which allow the
identification of the two total complex functors
HomologicalComplex₂ C c₁ c₂ ⥤ HomologicalComplex C c₁₂
and HomologicalComplex₂ C c₂ c₁ ⥤ HomologicalComplex C c₁₂
via the flip.
- symm : ∀ (i₁ : I₁) (i₂ : I₂), c₂.π c₁ c₁₂ (i₂, i₁) = c₁.π c₂ c₁₂ (i₁, i₂)
the signs involved in the symmetry isomorphism of the total complex
- σ_ε₁ : ∀ {i₁ i₁' : I₁}, c₁.Rel i₁ i₁' → ∀ (i₂ : I₂), TotalComplexShapeSymmetry.σ c₁ c₂ c₁₂ i₁ i₂ * c₁.ε₁ c₂ c₁₂ (i₁, i₂) = c₂.ε₂ c₁ c₁₂ (i₂, i₁) * TotalComplexShapeSymmetry.σ c₁ c₂ c₁₂ i₁' i₂
- σ_ε₂ : ∀ (i₁ : I₁) {i₂ i₂' : I₂}, c₂.Rel i₂ i₂' → TotalComplexShapeSymmetry.σ c₁ c₂ c₁₂ i₁ i₂ * c₁.ε₂ c₂ c₁₂ (i₁, i₂) = c₂.ε₁ c₁ c₁₂ (i₂, i₁) * TotalComplexShapeSymmetry.σ c₁ c₂ c₁₂ i₁ i₂'
Instances
The signs involved in the symmetry isomorphism of the total complex.
Equations
- c₁.σ c₂ c₁₂ i₁ i₂ = TotalComplexShapeSymmetry.σ c₁ c₂ c₁₂ i₁ i₂
Instances For
The symmetry bijection (π c₂ c₁ c₁₂ ⁻¹' {j}) ≃ (π c₁ c₂ c₁₂ ⁻¹' {j})
.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Equations
- One or more equations did not get rendered due to their size.
The obvious TotalComplexShapeSymmetry c₂ c₁ c₁₂
deduced from a
TotalComplexShapeSymmetry c₁ c₂ c₁₂
.
Equations
- TotalComplexShapeSymmetry.symmetry c₁ c₂ c₁₂ = { symm := ⋯, σ := fun (i₂ : I₂) (i₁ : I₁) => c₁.σ c₂ c₁₂ i₁ i₂, σ_ε₁ := ⋯, σ_ε₂ := ⋯ }
Instances For
This typeclass expresses that the signs given by [TotalComplexShapeSymmetry c₁ c₂ c₁₂]
and by [TotalComplexShapeSymmetry c₂ c₁ c₁₂]
are compatible.
- σ_symm : ∀ (i₁ : I₁) (i₂ : I₂), c₂.σ c₁ c₁₂ i₂ i₁ = c₁.σ c₂ c₁₂ i₁ i₂