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is_unit_iff_is_iso {C : Type u} [category.{v} C] {X : C} (f : End X) : is_unit (f : End X) ↔ is_iso f
⟨λ h, { out := ⟨h.unit.inv, ⟨h.unit.inv_val, h.unit.val_inv⟩⟩ }, λ h, by exactI ⟨⟨f, inv f, by simp, by simp⟩, rfl⟩⟩
lemma
category_theory.is_unit_iff_is_iso
category_theory
src/category_theory/endomorphism.lean
[ "algebra.hom.equiv.basic", "category_theory.groupoid", "category_theory.opposites", "group_theory.group_action.defs" ]
[ "is_unit" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
Aut (X : C)
X ≅ X
def
category_theory.Aut
category_theory
src/category_theory/endomorphism.lean
[ "algebra.hom.equiv.basic", "category_theory.groupoid", "category_theory.opposites", "group_theory.group_action.defs" ]
[]
Automorphisms of an object in a category. The order of arguments in multiplication agrees with `function.comp`, not with `category.comp`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inhabited : inhabited (Aut X)
⟨iso.refl X⟩
instance
category_theory.Aut.inhabited
category_theory
src/category_theory/endomorphism.lean
[ "algebra.hom.equiv.basic", "category_theory.groupoid", "category_theory.opposites", "group_theory.group_action.defs" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
Aut_mul_def (f g : Aut X) : f * g = g.trans f
rfl
lemma
category_theory.Aut.Aut_mul_def
category_theory
src/category_theory/endomorphism.lean
[ "algebra.hom.equiv.basic", "category_theory.groupoid", "category_theory.opposites", "group_theory.group_action.defs" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
Aut_inv_def (f : Aut X) : f ⁻¹ = f.symm
rfl
lemma
category_theory.Aut.Aut_inv_def
category_theory
src/category_theory/endomorphism.lean
[ "algebra.hom.equiv.basic", "category_theory.groupoid", "category_theory.opposites", "group_theory.group_action.defs" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
units_End_equiv_Aut : (End X)ˣ ≃* Aut X
{ to_fun := λ f, ⟨f.1, f.2, f.4, f.3⟩, inv_fun := λ f, ⟨f.1, f.2, f.4, f.3⟩, left_inv := λ ⟨f₁, f₂, f₃, f₄⟩, rfl, right_inv := λ ⟨f₁, f₂, f₃, f₄⟩, rfl, map_mul' := λ f g, by rcases f; rcases g; refl }
def
category_theory.Aut.units_End_equiv_Aut
category_theory
src/category_theory/endomorphism.lean
[ "algebra.hom.equiv.basic", "category_theory.groupoid", "category_theory.opposites", "group_theory.group_action.defs" ]
[ "inv_fun" ]
Units in the monoid of endomorphisms of an object are (multiplicatively) equivalent to automorphisms of that object.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
Aut_mul_equiv_of_iso {X Y : C} (h : X ≅ Y) : Aut X ≃* Aut Y
{ to_fun := λ x, ⟨h.inv ≫ x.hom ≫ h.hom, h.inv ≫ x.inv ≫ h.hom⟩, inv_fun := λ y, ⟨h.hom ≫ y.hom ≫ h.inv, h.hom ≫ y.inv ≫ h.inv⟩, left_inv := by tidy, right_inv := by tidy, map_mul' := by simp [Aut_mul_def] }
def
category_theory.Aut.Aut_mul_equiv_of_iso
category_theory
src/category_theory/endomorphism.lean
[ "algebra.hom.equiv.basic", "category_theory.groupoid", "category_theory.opposites", "group_theory.group_action.defs" ]
[ "inv_fun" ]
Isomorphisms induce isomorphisms of the automorphism group
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_End : End X →* End (f.obj X)
{ to_fun := functor.map f, map_mul' := λ x y, f.map_comp y x, map_one' := f.map_id X }
def
category_theory.functor.map_End
category_theory
src/category_theory/endomorphism.lean
[ "algebra.hom.equiv.basic", "category_theory.groupoid", "category_theory.opposites", "group_theory.group_action.defs" ]
[]
`f.map` as a monoid hom between endomorphism monoids.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_Aut : Aut X →* Aut (f.obj X)
{ to_fun := f.map_iso, map_mul' := λ x y, f.map_iso_trans y x, map_one' := f.map_iso_refl X }
def
category_theory.functor.map_Aut
category_theory
src/category_theory/endomorphism.lean
[ "algebra.hom.equiv.basic", "category_theory.groupoid", "category_theory.opposites", "group_theory.group_action.defs" ]
[]
`f.map_iso` as a group hom between automorphism groups.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unop_mono_of_epi {A B : Cᵒᵖ} (f : A ⟶ B) [epi f] : mono f.unop
⟨λ Z g h eq, quiver.hom.op_inj ((cancel_epi f).1 (quiver.hom.unop_inj eq))⟩
instance
category_theory.unop_mono_of_epi
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[ "quiver.hom.op_inj", "quiver.hom.unop_inj" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unop_epi_of_mono {A B : Cᵒᵖ} (f : A ⟶ B) [mono f] : epi f.unop
⟨λ Z g h eq, quiver.hom.op_inj ((cancel_mono f).1 (quiver.hom.unop_inj eq))⟩
instance
category_theory.unop_epi_of_mono
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[ "quiver.hom.op_inj", "quiver.hom.unop_inj" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
op_mono_of_epi {A B : C} (f : A ⟶ B) [epi f] : mono f.op
⟨λ Z g h eq, quiver.hom.unop_inj ((cancel_epi f).1 (quiver.hom.op_inj eq))⟩
instance
category_theory.op_mono_of_epi
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[ "quiver.hom.op_inj", "quiver.hom.unop_inj" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
op_epi_of_mono {A B : C} (f : A ⟶ B) [mono f] : epi f.op
⟨λ Z g h eq, quiver.hom.unop_inj ((cancel_mono f).1 (quiver.hom.op_inj eq))⟩
instance
category_theory.op_epi_of_mono
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[ "quiver.hom.op_inj", "quiver.hom.unop_inj" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
split_mono {X Y : C} (f : X ⟶ Y)
(retraction : Y ⟶ X) (id' : f ≫ retraction = 𝟙 X . obviously)
structure
category_theory.split_mono
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
A split monomorphism is a morphism `f : X ⟶ Y` with a given retraction `retraction f : Y ⟶ X` such that `f ≫ retraction f = 𝟙 X`. Every split monomorphism is a monomorphism.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_split_mono {X Y : C} (f : X ⟶ Y) : Prop
(exists_split_mono : nonempty (split_mono f))
class
category_theory.is_split_mono
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
`is_split_mono f` is the assertion that `f` admits a retraction
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_split_mono.mk' {X Y : C} {f : X ⟶ Y} (sm : split_mono f) : is_split_mono f
⟨nonempty.intro sm⟩
lemma
category_theory.is_split_mono.mk'
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
A constructor for `is_split_mono f` taking a `split_mono f` as an argument
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
split_epi {X Y : C} (f : X ⟶ Y)
(section_ : Y ⟶ X) (id' : section_ ≫ f = 𝟙 Y . obviously)
structure
category_theory.split_epi
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
A split epimorphism is a morphism `f : X ⟶ Y` with a given section `section_ f : Y ⟶ X` such that `section_ f ≫ f = 𝟙 Y`. (Note that `section` is a reserved keyword, so we append an underscore.) Every split epimorphism is an epimorphism.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_split_epi {X Y : C} (f : X ⟶ Y) : Prop
(exists_split_epi : nonempty (split_epi f))
class
category_theory.is_split_epi
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
`is_split_epi f` is the assertion that `f` admits a section
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_split_epi.mk' {X Y : C} {f : X ⟶ Y} (se : split_epi f) : is_split_epi f
⟨nonempty.intro se⟩
lemma
category_theory.is_split_epi.mk'
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
A constructor for `is_split_epi f` taking a `split_epi f` as an argument
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
retraction {X Y : C} (f : X ⟶ Y) [hf : is_split_mono f] : Y ⟶ X
hf.exists_split_mono.some.retraction
def
category_theory.retraction
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
The chosen retraction of a split monomorphism.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_split_mono.id {X Y : C} (f : X ⟶ Y) [hf : is_split_mono f] : f ≫ retraction f = 𝟙 X
hf.exists_split_mono.some.id
lemma
category_theory.is_split_mono.id
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
split_mono.split_epi {X Y : C} {f : X ⟶ Y} (sm : split_mono f) : split_epi (sm.retraction)
{ section_ := f, }
def
category_theory.split_mono.split_epi
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
The retraction of a split monomorphism has an obvious section.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
retraction_is_split_epi {X Y : C} (f : X ⟶ Y) [hf : is_split_mono f] : is_split_epi (retraction f)
is_split_epi.mk' (split_mono.split_epi _)
instance
category_theory.retraction_is_split_epi
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
The retraction of a split monomorphism is itself a split epimorphism.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_iso_of_epi_of_is_split_mono {X Y : C} (f : X ⟶ Y) [is_split_mono f] [epi f] : is_iso f
⟨⟨retraction f, ⟨by simp, by simp [← cancel_epi f]⟩⟩⟩
lemma
category_theory.is_iso_of_epi_of_is_split_mono
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
A split mono which is epi is an iso.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
section_ {X Y : C} (f : X ⟶ Y) [hf : is_split_epi f] : Y ⟶ X
hf.exists_split_epi.some.section_
def
category_theory.section_
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
The chosen section of a split epimorphism. (Note that `section` is a reserved keyword, so we append an underscore.)
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_split_epi.id {X Y : C} (f : X ⟶ Y) [hf : is_split_epi f] : section_ f ≫ f = 𝟙 Y
hf.exists_split_epi.some.id
lemma
category_theory.is_split_epi.id
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
split_epi.split_mono {X Y : C} {f : X ⟶ Y} (se : split_epi f) : split_mono (se.section_)
{ retraction := f, }
def
category_theory.split_epi.split_mono
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
The section of a split epimorphism has an obvious retraction.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
section_is_split_mono {X Y : C} (f : X ⟶ Y) [hf : is_split_epi f] : is_split_mono (section_ f)
is_split_mono.mk' (split_epi.split_mono _)
instance
category_theory.section_is_split_mono
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
The section of a split epimorphism is itself a split monomorphism.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_iso_of_mono_of_is_split_epi {X Y : C} (f : X ⟶ Y) [mono f] [is_split_epi f] : is_iso f
⟨⟨section_ f, ⟨by simp [← cancel_mono f], by simp⟩⟩⟩
lemma
category_theory.is_iso_of_mono_of_is_split_epi
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
A split epi which is mono is an iso.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_split_mono.of_iso {X Y : C} (f : X ⟶ Y) [is_iso f] : is_split_mono f
is_split_mono.mk' { retraction := inv f }
instance
category_theory.is_split_mono.of_iso
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
Every iso is a split mono.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_split_epi.of_iso {X Y : C} (f : X ⟶ Y) [is_iso f] : is_split_epi f
is_split_epi.mk' { section_ := inv f }
instance
category_theory.is_split_epi.of_iso
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
Every iso is a split epi.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
split_mono.mono {X Y : C} {f : X ⟶ Y} (sm : split_mono f) : mono f
{ right_cancellation := λ Z g h w, begin replace w := w =≫ sm.retraction, simpa using w, end }
lemma
category_theory.split_mono.mono
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_split_mono.mono {X Y : C} (f : X ⟶ Y) [hf : is_split_mono f] : mono f
hf.exists_split_mono.some.mono
instance
category_theory.is_split_mono.mono
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
Every split mono is a mono.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
split_epi.epi {X Y : C} {f : X ⟶ Y} (se : split_epi f) : epi f
{ left_cancellation := λ Z g h w, begin replace w := se.section_ ≫= w, simpa using w, end }
lemma
category_theory.split_epi.epi
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_split_epi.epi {X Y : C} (f : X ⟶ Y) [hf : is_split_epi f] : epi f
hf.exists_split_epi.some.epi
instance
category_theory.is_split_epi.epi
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
Every split epi is an epi.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_iso.of_mono_retraction' {X Y : C} {f : X ⟶ Y} (hf : split_mono f) [mono $ hf.retraction] : is_iso f
⟨⟨hf.retraction, ⟨by simp, (cancel_mono_id $ hf.retraction).mp (by simp)⟩⟩⟩
lemma
category_theory.is_iso.of_mono_retraction'
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
Every split mono whose retraction is mono is an iso.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_iso.of_mono_retraction {X Y : C} (f : X ⟶ Y) [hf : is_split_mono f] [hf' : mono $ retraction f] : is_iso f
@is_iso.of_mono_retraction' _ _ _ _ _ hf.exists_split_mono.some hf'
lemma
category_theory.is_iso.of_mono_retraction
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
Every split mono whose retraction is mono is an iso.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_iso.of_epi_section' {X Y : C} {f : X ⟶ Y} (hf : split_epi f) [epi $ hf.section_] : is_iso f
⟨⟨hf.section_, ⟨(cancel_epi_id $ hf.section_).mp (by simp), by simp⟩⟩⟩
lemma
category_theory.is_iso.of_epi_section'
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
Every split epi whose section is epi is an iso.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_iso.of_epi_section {X Y : C} (f : X ⟶ Y) [hf : is_split_epi f] [hf' : epi $ section_ f] : is_iso f
@is_iso.of_epi_section' _ _ _ _ _ hf.exists_split_epi.some hf'
lemma
category_theory.is_iso.of_epi_section
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
Every split epi whose section is epi is an iso.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
groupoid.of_trunc_split_mono (all_split_mono : ∀ {X Y : C} (f : X ⟶ Y), trunc (is_split_mono f)) : groupoid.{v₁} C
begin apply groupoid.of_is_iso, intros X Y f, trunc_cases all_split_mono f, trunc_cases all_split_mono (retraction f), apply is_iso.of_mono_retraction, end
def
category_theory.groupoid.of_trunc_split_mono
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[ "trunc" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
split_mono_category
(is_split_mono_of_mono : ∀ {X Y : C} (f : X ⟶ Y) [mono f], is_split_mono f)
class
category_theory.split_mono_category
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
A split mono category is a category in which every monomorphism is split.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
split_epi_category
(is_split_epi_of_epi : ∀ {X Y : C} (f : X ⟶ Y) [epi f], is_split_epi f)
class
category_theory.split_epi_category
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
A split epi category is a category in which every epimorphism is split.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_split_mono_of_mono [split_mono_category C] {X Y : C} (f : X ⟶ Y) [mono f] : is_split_mono f
split_mono_category.is_split_mono_of_mono _
lemma
category_theory.is_split_mono_of_mono
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
In a category in which every monomorphism is split, every monomorphism splits. This is not an instance because it would create an instance loop.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_split_epi_of_epi [split_epi_category C] {X Y : C} (f : X ⟶ Y) [epi f] : is_split_epi f
split_epi_category.is_split_epi_of_epi _
lemma
category_theory.is_split_epi_of_epi
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[]
In a category in which every epimorphism is split, every epimorphism splits. This is not an instance because it would create an instance loop.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
split_mono.map {X Y : C} {f : X ⟶ Y} (sm : split_mono f) (F : C ⥤ D ) : split_mono (F.map f)
{ retraction := F.map (sm.retraction), id' := by { rw [←functor.map_comp, split_mono.id, functor.map_id], } }
def
category_theory.split_mono.map
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[ "functor.map_id" ]
Split monomorphisms are also absolute monomorphisms.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
split_epi.map {X Y : C} {f : X ⟶ Y} (se : split_epi f) (F : C ⥤ D ) : split_epi (F.map f)
{ section_ := F.map (se.section_), id' := by { rw [←functor.map_comp, split_epi.id, functor.map_id], } }
def
category_theory.split_epi.map
category_theory
src/category_theory/epi_mono.lean
[ "category_theory.opposites", "category_theory.groupoid" ]
[ "functor.map_id" ]
Split epimorphisms are also absolute epimorphisms.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equivalence (C : Type u₁) [category.{v₁} C] (D : Type u₂) [category.{v₂} D]
mk' :: (functor : C ⥤ D) (inverse : D ⥤ C) (unit_iso : 𝟭 C ≅ functor ⋙ inverse) (counit_iso : inverse ⋙ functor ≅ 𝟭 D) (functor_unit_iso_comp' : ∀(X : C), functor.map ((unit_iso.hom : 𝟭 C ⟶ functor ⋙ inverse).app X) ≫ counit_iso.hom.app (functor.obj X) = 𝟙 (functor.obj X) . obviously)
structure
category_theory.equivalence
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[ "mk'" ]
We define an equivalence as a (half)-adjoint equivalence, a pair of functors with a unit and counit which are natural isomorphisms and the triangle law `Fη ≫ εF = 1`, or in other words the composite `F ⟶ FGF ⟶ F` is the identity. In `unit_inverse_comp`, we show that this is actually an adjoint equivalence, i.e.,...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unit (e : C ≌ D) : 𝟭 C ⟶ e.functor ⋙ e.inverse
e.unit_iso.hom
abbreviation
category_theory.equivalence.unit
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
The unit of an equivalence of categories.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
counit (e : C ≌ D) : e.inverse ⋙ e.functor ⟶ 𝟭 D
e.counit_iso.hom
abbreviation
category_theory.equivalence.counit
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
The counit of an equivalence of categories.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unit_inv (e : C ≌ D) : e.functor ⋙ e.inverse ⟶ 𝟭 C
e.unit_iso.inv
abbreviation
category_theory.equivalence.unit_inv
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
The inverse of the unit of an equivalence of categories.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
counit_inv (e : C ≌ D) : 𝟭 D ⟶ e.inverse ⋙ e.functor
e.counit_iso.inv
abbreviation
category_theory.equivalence.counit_inv
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
The inverse of the counit of an equivalence of categories.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equivalence_mk'_unit (functor inverse unit_iso counit_iso f) : (⟨functor, inverse, unit_iso, counit_iso, f⟩ : C ≌ D).unit = unit_iso.hom
rfl
lemma
category_theory.equivalence.equivalence_mk'_unit
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equivalence_mk'_counit (functor inverse unit_iso counit_iso f) : (⟨functor, inverse, unit_iso, counit_iso, f⟩ : C ≌ D).counit = counit_iso.hom
rfl
lemma
category_theory.equivalence.equivalence_mk'_counit
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equivalence_mk'_unit_inv (functor inverse unit_iso counit_iso f) : (⟨functor, inverse, unit_iso, counit_iso, f⟩ : C ≌ D).unit_inv = unit_iso.inv
rfl
lemma
category_theory.equivalence.equivalence_mk'_unit_inv
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equivalence_mk'_counit_inv (functor inverse unit_iso counit_iso f) : (⟨functor, inverse, unit_iso, counit_iso, f⟩ : C ≌ D).counit_inv = counit_iso.inv
rfl
lemma
category_theory.equivalence.equivalence_mk'_counit_inv
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
functor_unit_comp (e : C ≌ D) (X : C) : e.functor.map (e.unit.app X) ≫ e.counit.app (e.functor.obj X) = 𝟙 (e.functor.obj X)
e.functor_unit_iso_comp X
lemma
category_theory.equivalence.functor_unit_comp
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
counit_inv_functor_comp (e : C ≌ D) (X : C) : e.counit_inv.app (e.functor.obj X) ≫ e.functor.map (e.unit_inv.app X) = 𝟙 (e.functor.obj X)
begin erw [iso.inv_eq_inv (e.functor.map_iso (e.unit_iso.app X) ≪≫ e.counit_iso.app (e.functor.obj X)) (iso.refl _)], exact e.functor_unit_comp X end
lemma
category_theory.equivalence.counit_inv_functor_comp
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
counit_inv_app_functor (e : C ≌ D) (X : C) : e.counit_inv.app (e.functor.obj X) = e.functor.map (e.unit.app X)
by { symmetry, erw [←iso.comp_hom_eq_id (e.counit_iso.app _), functor_unit_comp], refl }
lemma
category_theory.equivalence.counit_inv_app_functor
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
counit_app_functor (e : C ≌ D) (X : C) : e.counit.app (e.functor.obj X) = e.functor.map (e.unit_inv.app X)
by { erw [←iso.hom_comp_eq_id (e.functor.map_iso (e.unit_iso.app X)), functor_unit_comp], refl }
lemma
category_theory.equivalence.counit_app_functor
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unit_inverse_comp (e : C ≌ D) (Y : D) : e.unit.app (e.inverse.obj Y) ≫ e.inverse.map (e.counit.app Y) = 𝟙 (e.inverse.obj Y)
begin rw [←id_comp (e.inverse.map _), ←map_id e.inverse, ←counit_inv_functor_comp, map_comp], dsimp, rw [←iso.hom_inv_id_assoc (e.unit_iso.app _) (e.inverse.map (e.functor.map _)), app_hom, app_inv], slice_lhs 2 3 { erw [e.unit.naturality] }, slice_lhs 1 2 { erw [e.unit.naturality] }, slice_lhs 4 4 ...
lemma
category_theory.equivalence.unit_inverse_comp
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[ "map_comp", "map_id" ]
The other triangle equality. The proof follows the following proof in Globular: http://globular.science/1905.001
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inverse_counit_inv_comp (e : C ≌ D) (Y : D) : e.inverse.map (e.counit_inv.app Y) ≫ e.unit_inv.app (e.inverse.obj Y) = 𝟙 (e.inverse.obj Y)
begin erw [iso.inv_eq_inv (e.unit_iso.app (e.inverse.obj Y) ≪≫ e.inverse.map_iso (e.counit_iso.app Y)) (iso.refl _)], exact e.unit_inverse_comp Y end
lemma
category_theory.equivalence.inverse_counit_inv_comp
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unit_app_inverse (e : C ≌ D) (Y : D) : e.unit.app (e.inverse.obj Y) = e.inverse.map (e.counit_inv.app Y)
by { erw [←iso.comp_hom_eq_id (e.inverse.map_iso (e.counit_iso.app Y)), unit_inverse_comp], refl }
lemma
category_theory.equivalence.unit_app_inverse
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unit_inv_app_inverse (e : C ≌ D) (Y : D) : e.unit_inv.app (e.inverse.obj Y) = e.inverse.map (e.counit.app Y)
by { symmetry, erw [←iso.hom_comp_eq_id (e.unit_iso.app _), unit_inverse_comp], refl }
lemma
category_theory.equivalence.unit_inv_app_inverse
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
fun_inv_map (e : C ≌ D) (X Y : D) (f : X ⟶ Y) : e.functor.map (e.inverse.map f) = e.counit.app X ≫ f ≫ e.counit_inv.app Y
(nat_iso.naturality_2 (e.counit_iso) f).symm
lemma
category_theory.equivalence.fun_inv_map
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_fun_map (e : C ≌ D) (X Y : C) (f : X ⟶ Y) : e.inverse.map (e.functor.map f) = e.unit_inv.app X ≫ f ≫ e.unit.app Y
(nat_iso.naturality_1 (e.unit_iso) f).symm
lemma
category_theory.equivalence.inv_fun_map
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
adjointify_η : 𝟭 C ≅ F ⋙ G
calc 𝟭 C ≅ F ⋙ G : η ... ≅ F ⋙ (𝟭 D ⋙ G) : iso_whisker_left F (left_unitor G).symm ... ≅ F ⋙ ((G ⋙ F) ⋙ G) : iso_whisker_left F (iso_whisker_right ε.symm G) ... ≅ F ⋙ (G ⋙ (F ⋙ G)) : iso_whisker_left F (associator G F G) ... ≅ (F ⋙ G) ⋙ (F ⋙ G) : (associator F G (F ⋙ G)).symm ... ≅ 𝟭 C...
def
category_theory.equivalence.adjointify_η
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
If `η : 𝟭 C ≅ F ⋙ G` is part of a (not necessarily half-adjoint) equivalence, we can upgrade it to a refined natural isomorphism `adjointify_η η : 𝟭 C ≅ F ⋙ G` which exhibits the properties required for a half-adjoint equivalence. See `equivalence.mk`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
adjointify_η_ε (X : C) : F.map ((adjointify_η η ε).hom.app X) ≫ ε.hom.app (F.obj X) = 𝟙 (F.obj X)
begin dsimp [adjointify_η], simp, have := ε.hom.naturality (F.map (η.inv.app X)), dsimp at this, rw [this], clear this, rw [←assoc _ _ (F.map _)], have := ε.hom.naturality (ε.inv.app $ F.obj X), dsimp at this, rw [this], clear this, have := (ε.app $ F.obj X).hom_inv_id, dsimp at this, rw [this], clear this, ...
lemma
category_theory.equivalence.adjointify_η_ε
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk (F : C ⥤ D) (G : D ⥤ C) (η : 𝟭 C ≅ F ⋙ G) (ε : G ⋙ F ≅ 𝟭 D) : C ≌ D
⟨F, G, adjointify_η η ε, ε, adjointify_η_ε η ε⟩
definition
category_theory.equivalence.mk
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
Every equivalence of categories consisting of functors `F` and `G` such that `F ⋙ G` and `G ⋙ F` are naturally isomorphic to identity functors can be transformed into a half-adjoint equivalence without changing `F` or `G`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
refl : C ≌ C
⟨𝟭 C, 𝟭 C, iso.refl _, iso.refl _, λ X, category.id_comp _⟩
def
category_theory.equivalence.refl
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
Equivalence of categories is reflexive.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
symm (e : C ≌ D) : D ≌ C
⟨e.inverse, e.functor, e.counit_iso.symm, e.unit_iso.symm, e.inverse_counit_inv_comp⟩
def
category_theory.equivalence.symm
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
Equivalence of categories is symmetric.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
trans (e : C ≌ D) (f : D ≌ E) : C ≌ E
{ functor := e.functor ⋙ f.functor, inverse := f.inverse ⋙ e.inverse, unit_iso := begin refine iso.trans e.unit_iso _, exact iso_whisker_left e.functor (iso_whisker_right f.unit_iso e.inverse) , end, counit_iso := begin refine iso.trans _ f.counit_iso, exact iso_whisker_left f.inverse (iso_w...
def
category_theory.equivalence.trans
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[ "functor.map_id" ]
Equivalence of categories is transitive.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
fun_inv_id_assoc (e : C ≌ D) (F : C ⥤ E) : e.functor ⋙ e.inverse ⋙ F ≅ F
(functor.associator _ _ _).symm ≪≫ iso_whisker_right e.unit_iso.symm F ≪≫ F.left_unitor
def
category_theory.equivalence.fun_inv_id_assoc
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
Composing a functor with both functors of an equivalence yields a naturally isomorphic functor.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
fun_inv_id_assoc_hom_app (e : C ≌ D) (F : C ⥤ E) (X : C) : (fun_inv_id_assoc e F).hom.app X = F.map (e.unit_inv.app X)
by { dsimp [fun_inv_id_assoc], tidy }
lemma
category_theory.equivalence.fun_inv_id_assoc_hom_app
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
fun_inv_id_assoc_inv_app (e : C ≌ D) (F : C ⥤ E) (X : C) : (fun_inv_id_assoc e F).inv.app X = F.map (e.unit.app X)
by { dsimp [fun_inv_id_assoc], tidy }
lemma
category_theory.equivalence.fun_inv_id_assoc_inv_app
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_fun_id_assoc (e : C ≌ D) (F : D ⥤ E) : e.inverse ⋙ e.functor ⋙ F ≅ F
(functor.associator _ _ _).symm ≪≫ iso_whisker_right e.counit_iso F ≪≫ F.left_unitor
def
category_theory.equivalence.inv_fun_id_assoc
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
Composing a functor with both functors of an equivalence yields a naturally isomorphic functor.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_fun_id_assoc_hom_app (e : C ≌ D) (F : D ⥤ E) (X : D) : (inv_fun_id_assoc e F).hom.app X = F.map (e.counit.app X)
by { dsimp [inv_fun_id_assoc], tidy }
lemma
category_theory.equivalence.inv_fun_id_assoc_hom_app
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_fun_id_assoc_inv_app (e : C ≌ D) (F : D ⥤ E) (X : D) : (inv_fun_id_assoc e F).inv.app X = F.map (e.counit_inv.app X)
by { dsimp [inv_fun_id_assoc], tidy }
lemma
category_theory.equivalence.inv_fun_id_assoc_inv_app
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
congr_left (e : C ≌ D) : (C ⥤ E) ≌ (D ⥤ E)
equivalence.mk ((whiskering_left _ _ _).obj e.inverse) ((whiskering_left _ _ _).obj e.functor) (nat_iso.of_components (λ F, (e.fun_inv_id_assoc F).symm) (by tidy)) (nat_iso.of_components (λ F, e.inv_fun_id_assoc F) (by tidy))
def
category_theory.equivalence.congr_left
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
If `C` is equivalent to `D`, then `C ⥤ E` is equivalent to `D ⥤ E`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
congr_right (e : C ≌ D) : (E ⥤ C) ≌ (E ⥤ D)
equivalence.mk ((whiskering_right _ _ _).obj e.functor) ((whiskering_right _ _ _).obj e.inverse) (nat_iso.of_components (λ F, F.right_unitor.symm ≪≫ iso_whisker_left F e.unit_iso ≪≫ functor.associator _ _ _) (by tidy)) (nat_iso.of_components (λ F, functor.associator _ _ _ ≪≫ iso_whisker_left F e.cou...
def
category_theory.equivalence.congr_right
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
If `C` is equivalent to `D`, then `E ⥤ C` is equivalent to `E ⥤ D`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cancel_unit_right {X Y : C} (f f' : X ⟶ Y) : f ≫ e.unit.app Y = f' ≫ e.unit.app Y ↔ f = f'
by simp only [cancel_mono]
lemma
category_theory.equivalence.cancel_unit_right
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cancel_unit_inv_right {X Y : C} (f f' : X ⟶ e.inverse.obj (e.functor.obj Y)) : f ≫ e.unit_inv.app Y = f' ≫ e.unit_inv.app Y ↔ f = f'
by simp only [cancel_mono]
lemma
category_theory.equivalence.cancel_unit_inv_right
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cancel_counit_right {X Y : D} (f f' : X ⟶ e.functor.obj (e.inverse.obj Y)) : f ≫ e.counit.app Y = f' ≫ e.counit.app Y ↔ f = f'
by simp only [cancel_mono]
lemma
category_theory.equivalence.cancel_counit_right
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cancel_counit_inv_right {X Y : D} (f f' : X ⟶ Y) : f ≫ e.counit_inv.app Y = f' ≫ e.counit_inv.app Y ↔ f = f'
by simp only [cancel_mono]
lemma
category_theory.equivalence.cancel_counit_inv_right
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cancel_unit_right_assoc {W X X' Y : C} (f : W ⟶ X) (g : X ⟶ Y) (f' : W ⟶ X') (g' : X' ⟶ Y) : f ≫ g ≫ e.unit.app Y = f' ≫ g' ≫ e.unit.app Y ↔ f ≫ g = f' ≫ g'
by simp only [←category.assoc, cancel_mono]
lemma
category_theory.equivalence.cancel_unit_right_assoc
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cancel_counit_inv_right_assoc {W X X' Y : D} (f : W ⟶ X) (g : X ⟶ Y) (f' : W ⟶ X') (g' : X' ⟶ Y) : f ≫ g ≫ e.counit_inv.app Y = f' ≫ g' ≫ e.counit_inv.app Y ↔ f ≫ g = f' ≫ g'
by simp only [←category.assoc, cancel_mono]
lemma
category_theory.equivalence.cancel_counit_inv_right_assoc
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cancel_unit_right_assoc' {W X X' Y Y' Z : C} (f : W ⟶ X) (g : X ⟶ Y) (h : Y ⟶ Z) (f' : W ⟶ X') (g' : X' ⟶ Y') (h' : Y' ⟶ Z) : f ≫ g ≫ h ≫ e.unit.app Z = f' ≫ g' ≫ h' ≫ e.unit.app Z ↔ f ≫ g ≫ h = f' ≫ g' ≫ h'
by simp only [←category.assoc, cancel_mono]
lemma
category_theory.equivalence.cancel_unit_right_assoc'
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cancel_counit_inv_right_assoc' {W X X' Y Y' Z : D} (f : W ⟶ X) (g : X ⟶ Y) (h : Y ⟶ Z) (f' : W ⟶ X') (g' : X' ⟶ Y') (h' : Y' ⟶ Z) : f ≫ g ≫ h ≫ e.counit_inv.app Z = f' ≫ g' ≫ h' ≫ e.counit_inv.app Z ↔ f ≫ g ≫ h = f' ≫ g' ≫ h'
by simp only [←category.assoc, cancel_mono]
lemma
category_theory.equivalence.cancel_counit_inv_right_assoc'
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pow_nat (e : C ≌ C) : ℕ → (C ≌ C)
| 0 := equivalence.refl | 1 := e | (n+2) := e.trans (pow_nat (n+1))
def
category_theory.equivalence.pow_nat
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
Natural number powers of an auto-equivalence. Use `(^)` instead.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pow (e : C ≌ C) : ℤ → (C ≌ C)
| (int.of_nat n) := e.pow_nat n | (int.neg_succ_of_nat n) := e.symm.pow_nat (n+1)
def
category_theory.equivalence.pow
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
Powers of an auto-equivalence. Use `(^)` instead.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pow_zero (e : C ≌ C) : e^(0 : ℤ) = equivalence.refl
rfl
lemma
category_theory.equivalence.pow_zero
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[ "pow_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pow_one (e : C ≌ C) : e^(1 : ℤ) = e
rfl
lemma
category_theory.equivalence.pow_one
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[ "pow_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pow_neg_one (e : C ≌ C) : e^(-1 : ℤ) = e.symm
rfl
lemma
category_theory.equivalence.pow_neg_one
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_equivalence (F : C ⥤ D)
mk' :: (inverse : D ⥤ C) (unit_iso : 𝟭 C ≅ F ⋙ inverse) (counit_iso : inverse ⋙ F ≅ 𝟭 D) (functor_unit_iso_comp' : ∀ (X : C), F.map ((unit_iso.hom : 𝟭 C ⟶ F ⋙ inverse).app X) ≫ counit_iso.hom.app (F.obj X) = 𝟙 (F.obj X) . obviously)
class
category_theory.is_equivalence
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[ "mk'" ]
A functor that is part of a (half) adjoint equivalence
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_equivalence (F : C ≌ D) : is_equivalence F.functor
{ ..F }
instance
category_theory.is_equivalence.of_equivalence
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_equivalence_inverse (F : C ≌ D) : is_equivalence F.inverse
is_equivalence.of_equivalence F.symm
instance
category_theory.is_equivalence.of_equivalence_inverse
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk {F : C ⥤ D} (G : D ⥤ C) (η : 𝟭 C ≅ F ⋙ G) (ε : G ⋙ F ≅ 𝟭 D) : is_equivalence F
⟨G, adjointify_η η ε, ε, adjointify_η_ε η ε⟩
definition
category_theory.is_equivalence.mk
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
To see that a functor is an equivalence, it suffices to provide an inverse functor `G` such that `F ⋙ G` and `G ⋙ F` are naturally isomorphic to identity functors.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
as_equivalence (F : C ⥤ D) [is_equivalence F] : C ≌ D
⟨F, is_equivalence.inverse F, is_equivalence.unit_iso, is_equivalence.counit_iso, is_equivalence.functor_unit_iso_comp⟩
def
category_theory.functor.as_equivalence
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
Interpret a functor that is an equivalence as an equivalence.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_equivalence_refl : is_equivalence (𝟭 C)
is_equivalence.of_equivalence equivalence.refl
instance
category_theory.functor.is_equivalence_refl
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv (F : C ⥤ D) [is_equivalence F] : D ⥤ C
is_equivalence.inverse F
def
category_theory.functor.inv
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
The inverse functor of a functor that is an equivalence.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_equivalence_inv (F : C ⥤ D) [is_equivalence F] : is_equivalence F.inv
is_equivalence.of_equivalence F.as_equivalence.symm
instance
category_theory.functor.is_equivalence_inv
category_theory
src/category_theory/equivalence.lean
[ "category_theory.functor.fully_faithful", "category_theory.full_subcategory", "category_theory.whiskering", "category_theory.essential_image", "tactic.slice" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83