Documentation

Mathlib.CategoryTheory.Sites.PseudofunctorSheafOver

Sheaves on Over categories, as a pseudofunctor #

Given a Grothendieck topology J on a category C and a category A, we define the pseudofunctor J.pseudofunctorOver A : Pseudofunctor (LocallyDiscrete Cᵒᵖ) Cat which sends X : C to the category of sheaves on Over X with values in A.

Given a Grothendieck topology J on a category C and a category A, this is the pseudofunctor which sends X : C to the categories of sheaves on Over X with values in A.

Equations
  • One or more equations did not get rendered due to their size.
Instances For
    @[simp]
    theorem CategoryTheory.GrothendieckTopology.pseudofunctorOver_mapComp_hom_toNatTrans_app_val_app {C : Type u} [Category.{v, u} C] (J : GrothendieckTopology C) (A : Type u') [Category.{v', u'} A] {a✝ b✝ c✝ : LocallyDiscrete Cᵒᵖ} (x✝ : a✝ b✝) (x✝¹ : b✝ c✝) (X : Sheaf (J.over (Opposite.unop a✝.as)) A) (X✝ : (Over (Opposite.unop c✝.as))ᵒᵖ) :
    (((J.pseudofunctorOver A).mapComp x✝ x✝¹).hom.toNatTrans.app X).val.app X✝ = X.val.map ((Over.mapComp x✝¹.as.unop x✝.as.unop).inv.app (Opposite.unop X✝)).op
    @[simp]
    theorem CategoryTheory.GrothendieckTopology.pseudofunctorOver_mapComp_inv_toNatTrans_app_val_app {C : Type u} [Category.{v, u} C] (J : GrothendieckTopology C) (A : Type u') [Category.{v', u'} A] {a✝ b✝ c✝ : LocallyDiscrete Cᵒᵖ} (x✝ : a✝ b✝) (x✝¹ : b✝ c✝) (X : Sheaf (J.over (Opposite.unop a✝.as)) A) (X✝ : (Over (Opposite.unop c✝.as))ᵒᵖ) :
    (((J.pseudofunctorOver A).mapComp x✝ x✝¹).inv.toNatTrans.app X).val.app X✝ = X.val.map ((Over.mapComp x✝¹.as.unop x✝.as.unop).hom.app (Opposite.unop X✝)).op