Resolutions for a morphism of localizers #
Given a morphism of localizers Φ : LocalizerMorphism W₁ W₂
(i.e. W₁
and W₂
are
morphism properties on categories C₁
and C₂
, and we have a functor
Φ.functor : C₁ ⥤ C₂
which sends morphisms in W₁
to morphisms in W₂
), we introduce
the notion of right resolutions of objects in C₂
: if X₂ : C₂
.
A right resolution consists of an object X₁ : C₁
and a morphism
w : X₂ ⟶ Φ.functor.obj X₁
that is in W₂
. Then, the typeclass
Φ.HasRightResolutions
holds when any X₂ : C₂
has a right resolution.
The type of right resolutions Φ.RightResolution X₂
is endowed with a category
structure when the morphism property W₁
is multiplicative.
Future works #
- formalize right derivability structures as localizer morphisms admitting right resolutions and forming a Guitart exact square, as it is defined in [the paper by Kahn and Maltsiniotis][KahnMaltsiniotis2008] (TODO @joelriou)
- show that if
C
is an abelian category with enough injectives, there is a derivability structure associated to the inclusion of the full subcategory of complexes of injective objects into the bounded below homotopy category ofC
(TODO @joelriou) - formalize dual results
References #
- [Bruno Kahn and Georges Maltsiniotis, Structures de dérivabilité][KahnMaltsiniotis2008]
The category of resolutions of an object in the target category of a localizer morphism.
- X₁ : C₁
an object in the source category
- w : X₂ ⟶ Φ.functor.toPrefunctor.obj self.X₁
a morphism to an object of the form
Φ.functor.obj X₁
- hw : W₂ self.w
Instances For
A localizer morphism has right resolutions when any object has a right resolution.
Equations
Instances For
The type of morphisms in the category Φ.RightResolution X₂
(when W₁
is multiplicative).
- f : R.X₁ ⟶ R'.X₁
a morphism in the source category
- hf : W₁ self.f
- comm : CategoryTheory.CategoryStruct.comp R.w (Φ.functor.toPrefunctor.map self.f) = R'.w
Instances For
The identity of a object in Φ.RightResolution X₂
.
Equations
- One or more equations did not get rendered due to their size.
Instances For
The composition of morphisms in Φ.RightResolution X₂
.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Equations
- CategoryTheory.LocalizerMorphism.RightResolution.instCategoryRightResolution = CategoryTheory.Category.mk