Predicate for localized categories #
In this file, a predicate L.IsLocalization W
is introduced for a functor L : C ⥤ D
and W : MorphismProperty C
: it expresses that L
identifies D
with the localized
category of C
with respect to W
(up to equivalence).
We introduce a universal property StrictUniversalPropertyFixedTarget L W E
which
states that L
inverts the morphisms in W
and that all functors C ⥤ E
inverting
W
uniquely factors as a composition of L ⋙ G
with G : D ⥤ E
. Such universal
properties are inputs for the constructor IsLocalization.mk'
for L.IsLocalization W
.
When L : C ⥤ D
is a localization functor for W : MorphismProperty
(i.e. when
[L.IsLocalization W]
holds), for any category E
, there is
an equivalence FunctorEquivalence L W E : (D ⥤ E) ≌ (W.FunctorsInverting E)
that is induced by the composition with the functor L
. When two functors
F : C ⥤ E
and F' : D ⥤ E
correspond via this equivalence, we shall say
that F'
lifts F
, and the associated isomorphism L ⋙ F' ≅ F
is the
datum that is part of the class Lifting L W F F'
. The functions
liftNatTrans
and liftNatIso
can be used to lift natural transformations
and natural isomorphisms between functors.
The predicate expressing that, up to equivalence, a functor L : C ⥤ D
identifies the category D
with the localized category of C
with respect
to W : MorphismProperty C
.
- inverts : W.IsInvertedBy L
the functor inverts the given
MorphismProperty
- isEquivalence : (CategoryTheory.Localization.Construction.lift L ⋯).IsEquivalence
the induced functor from the constructed localized category is an equivalence
Instances
the functor inverts the given MorphismProperty
the induced functor from the constructed localized category is an equivalence
Equations
- ⋯ = ⋯
This universal property states that a functor L : C ⥤ D
inverts morphisms
in W
and the all functors D ⥤ E
(for a fixed category E
) uniquely factors
through L
.
- inverts : W.IsInvertedBy L
the functor
L
invertsW
- lift : (F : CategoryTheory.Functor C E) → W.IsInvertedBy F → CategoryTheory.Functor D E
any functor
C ⥤ E
which invertsW
can be lifted as a functorD ⥤ E
- fac : ∀ (F : CategoryTheory.Functor C E) (hF : W.IsInvertedBy F), L.comp (self.lift F hF) = F
there is a factorisation involving the lifted functor
- uniq : ∀ (F₁ F₂ : CategoryTheory.Functor D E), L.comp F₁ = L.comp F₂ → F₁ = F₂
uniqueness of the lifted functor
Instances For
the functor L
inverts W
there is a factorisation involving the lifted functor
uniqueness of the lifted functor
The localized category W.Localization
that was constructed satisfies
the universal property of the localization.
Equations
- CategoryTheory.Localization.strictUniversalPropertyFixedTargetQ W E = { inverts := ⋯, lift := CategoryTheory.Localization.Construction.lift, fac := ⋯, uniq := ⋯ }
Instances For
When W
consists of isomorphisms, the identity satisfies the universal property
of the localization.
Equations
- CategoryTheory.Localization.strictUniversalPropertyFixedTargetId W E hW = { inverts := ⋯, lift := fun (F : CategoryTheory.Functor C E) (x : W.IsInvertedBy F) => F, fac := ⋯, uniq := ⋯ }
Instances For
The isomorphism L.obj X ≅ L.obj Y
that is deduced from a morphism f : X ⟶ Y
which
belongs to W
, when L.IsLocalization W
.
Equations
- CategoryTheory.Localization.isoOfHom L W f hf = CategoryTheory.asIso (L.map f)
Instances For
Equations
- ⋯ = ⋯
A chosen equivalence of categories W.Localization ≅ D
for a functor
L : C ⥤ D
which satisfies L.IsLocalization W
. This shall be used in
order to deduce properties of L
from properties of W.Q
.
Equations
- CategoryTheory.Localization.equivalenceFromModel L W = (CategoryTheory.Localization.Construction.lift L ⋯).asEquivalence
Instances For
Via the equivalence of categories equivalence_from_model L W : W.localization ≌ D
,
one may identify the functors W.Q
and L
.
Equations
Instances For
Via the equivalence of categories equivalence_from_model L W : W.localization ≌ D
,
one may identify the functors L
and W.Q
.
Equations
- One or more equations did not get rendered due to their size.
Instances For
The functor (D ⥤ E) ⥤ W.functors_inverting E
induced by the composition
with a localization functor L : C ⥤ D
with respect to W : morphism_property C
.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Equations
- ⋯ = ⋯
The equivalence of categories (D ⥤ E) ≌ (W.FunctorsInverting E)
induced by
the composition with a localization functor L : C ⥤ D
with respect to
W : MorphismProperty C
.
Equations
- CategoryTheory.Localization.functorEquivalence L W E = (CategoryTheory.Localization.whiskeringLeftFunctor L W E).asEquivalence
Instances For
The functor (D ⥤ E) ⥤ (C ⥤ E)
given by the composition with a localization
functor L : C ⥤ D
with respect to W : MorphismProperty C
.
Equations
- CategoryTheory.Localization.whiskeringLeftFunctor' L W E = (CategoryTheory.whiskeringLeft C D E).obj L
Instances For
Equations
- ⋯ = ⋯
Equations
- ⋯ = ⋯
When L : C ⥤ D
is a localization functor for W : MorphismProperty C
and
F : C ⥤ E
is a functor, we shall say that F' : D ⥤ E
lifts F
if the obvious diagram
is commutative up to an isomorphism.
- iso' : L.comp F' ≅ F
the isomorphism relating the localization functor and the two other given functors
Instances
The distinguished isomorphism L ⋙ F' ≅ F
given by [Lifting L W F F']
.
Equations
Instances For
Given a localization functor L : C ⥤ D
for W : MorphismProperty C
and
a functor F : C ⥤ E
which inverts W
, this is a choice of functor
D ⥤ E
which lifts F
.
Equations
- CategoryTheory.Localization.lift F hF L = (CategoryTheory.Localization.functorEquivalence L W E).inverse.obj { obj := F, property := hF }
Instances For
Equations
- One or more equations did not get rendered due to their size.
The canonical isomorphism L ⋙ lift F hF L ≅ F
for any functor F : C ⥤ E
which inverts W
, when L : C ⥤ D
is a localization functor for W
.
Equations
Instances For
Equations
- CategoryTheory.Localization.liftingConstructionLift F hF = { iso' := CategoryTheory.eqToIso ⋯ }
Given a localization functor L : C ⥤ D
for W : MorphismProperty C
,
if (F₁' F₂' : D ⥤ E)
are functors which lifts functors (F₁ F₂ : C ⥤ E)
,
a natural transformation τ : F₁ ⟶ F₂
uniquely lifts to a natural transformation F₁' ⟶ F₂'
.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Given a localization functor L : C ⥤ D
for W : MorphismProperty C
,
if (F₁' F₂' : D ⥤ E)
are functors which lifts functors (F₁ F₂ : C ⥤ E)
,
a natural isomorphism τ : F₁ ⟶ F₂
lifts to a natural isomorphism F₁' ⟶ F₂'
.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Equations
- CategoryTheory.Localization.Lifting.compRight L W F F' G = { iso' := CategoryTheory.isoWhiskerRight (CategoryTheory.Localization.Lifting.iso L W F F') G }
Equations
- CategoryTheory.Localization.Lifting.id L W = { iso' := L.rightUnitor }
Equations
- CategoryTheory.Localization.Lifting.compLeft L W F = { iso' := CategoryTheory.Iso.refl (L.comp F) }
Given a localization functor L : C ⥤ D
for W : MorphismProperty C
,
if F₁' : D ⥤ E
lifts a functor F₁ : C ⥤ D
, then a functor F₂'
which
is isomorphic to F₁'
also lifts a functor F₂
that is isomorphic to F₁
.
Equations
- CategoryTheory.Localization.Lifting.ofIsos L W e e' = { iso' := CategoryTheory.isoWhiskerLeft L e'.symm ≪≫ CategoryTheory.Localization.Lifting.iso L W F₁ F₁' ≪≫ e }
Instances For
If L : C ⥤ D
is a localization for W : MorphismProperty C
, then it is also
the case of a functor obtained by post-composing L
with an equivalence of categories.
Equations
- ⋯ = ⋯
If L₁ : C ⥤ D₁
and L₂ : C ⥤ D₂
are two localization functors for the
same MorphismProperty C
, this is an equivalence of categories D₁ ≌ D₂
.
Equations
- CategoryTheory.Localization.uniq L₁ L₂ W' = (CategoryTheory.Localization.equivalenceFromModel L₁ W').symm.trans (CategoryTheory.Localization.equivalenceFromModel L₂ W')
Instances For
The functor of equivalence of localized categories given by Localization.uniq
is
compatible with the localization functors.
Equations
- One or more equations did not get rendered due to their size.
Instances For
The inverse functor of equivalence of localized categories given by Localization.uniq
is
compatible with the localization functors.
Equations
Instances For
Equations
- CategoryTheory.Localization.instLiftingFunctorUniq L₁ L₂ W' = { iso' := CategoryTheory.Localization.compUniqFunctor L₁ L₂ W' }
Equations
- CategoryTheory.Localization.instLiftingInverseUniq L₁ L₂ W' = { iso' := CategoryTheory.Localization.compUniqInverse L₁ L₂ W' }
If L₁ : C ⥤ D₁
and L₂ : C ⥤ D₂
are two localization functors for the
same MorphismProperty C
, any functor F : D₁ ⥤ D₂
equipped with an isomorphism
L₁ ⋙ F ≅ L₂
is isomorphic to the functor of the equivalence given by uniq
.
Equations
- CategoryTheory.Localization.isoUniqFunctor L₁ L₂ W' F e = CategoryTheory.Localization.liftNatIso L₁ W' L₂ L₂ F (CategoryTheory.Localization.uniq L₁ L₂ W').functor (CategoryTheory.Iso.refl L₂)
Instances For
The property that two morphisms become equal in the localized category.
Equations
- CategoryTheory.AreEqualizedByLocalization W f g = (W.Q.map f = W.Q.map g)