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
Instances
The map I₁ × I₂ → I₁₂
on indices given by TotalComplexShape c₁ c₂ c₁₂
.
Equations
Instances For
The sign of the horizontal differential in the total complex.
Equations
Instances For
The sign of the vertical differential in the total complex.
Equations
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
.
the signs which appear in the vertical differential of the total complex
Instances
The signs which appear in the vertical differential of the total complex.
Equations
Instances For
Equations
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).
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
Instances For
The GradedObject.BifunctorComp₁₂IndexData
which arises from complex shapes.
Equations
Instances For
The GradedObject.BifunctorComp₂₃IndexData
which arises from complex shapes.
Equations
Instances For
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.
the signs involved in the symmetry isomorphism of the total complex
Instances
The signs involved in the symmetry isomorphism of the total complex.
Equations
Instances For
The symmetry bijection (π c₂ c₁ c₁₂ ⁻¹' {j}) ≃ (π c₁ c₂ c₁₂ ⁻¹' {j})
.
Equations
Instances For
Equations
The obvious TotalComplexShapeSymmetry c₂ c₁ c₁₂
deduced from a
TotalComplexShapeSymmetry c₁ c₂ c₁₂
.
Equations
Instances For
This typeclass expresses that the signs given by [TotalComplexShapeSymmetry c₁ c₂ c₁₂]
and by [TotalComplexShapeSymmetry c₂ c₁ c₁₂]
are compatible.