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left_adjoint_lift_struct_equiv : sq.lift_struct ≃ (sq.left_adjoint adj).lift_struct
{ to_fun := λ l, { l := (adj.hom_equiv _ _).symm l.l, fac_left' := by rw [← adj.hom_equiv_naturality_left_symm, l.fac_left], fac_right' := by rw [← adj.hom_equiv_naturality_right_symm, l.fac_right], }, inv_fun := λ l, { l := (adj.hom_equiv _ _) l.l, fac_left' := begin rw [← adj.hom_equiv_natural...
def
category_theory.comm_sq.left_adjoint_lift_struct_equiv
category_theory.lifting_properties
src/category_theory/lifting_properties/adjunction.lean
[ "category_theory.lifting_properties.basic", "category_theory.adjunction.basic" ]
[ "adj", "inv_fun" ]
The liftings of a commutative are in bijection with the liftings of its (left) adjoint square.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
left_adjoint_has_lift_iff : has_lift (sq.left_adjoint adj) ↔ has_lift sq
begin simp only [has_lift.iff], exact equiv.nonempty_congr (sq.left_adjoint_lift_struct_equiv adj).symm, end
lemma
category_theory.comm_sq.left_adjoint_has_lift_iff
category_theory.lifting_properties
src/category_theory/lifting_properties/adjunction.lean
[ "category_theory.lifting_properties.basic", "category_theory.adjunction.basic" ]
[ "adj", "equiv.nonempty_congr" ]
A (left) adjoint square has a lifting if and only if the original square has a lifting.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_lifting_property_iff (adj : G ⊣ F) {A B : C} {X Y : D} (i : A ⟶ B) (p : X ⟶ Y) : has_lifting_property (G.map i) p ↔ has_lifting_property i (F.map p)
begin split; introI; constructor; intros f g sq, { rw ← sq.left_adjoint_has_lift_iff adj, apply_instance, }, { rw ← sq.right_adjoint_has_lift_iff adj, apply_instance, }, end
lemma
category_theory.adjunction.has_lifting_property_iff
category_theory.lifting_properties
src/category_theory/lifting_properties/adjunction.lean
[ "category_theory.lifting_properties.basic", "category_theory.adjunction.basic" ]
[ "adj" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_lifting_property : Prop
(sq_has_lift : ∀ {f : A ⟶ X} {g : B ⟶ Y} (sq : comm_sq f i p g), sq.has_lift)
class
category_theory.has_lifting_property
category_theory.lifting_properties
src/category_theory/lifting_properties/basic.lean
[ "category_theory.comm_sq" ]
[]
`has_lifting_property i p` means that `i` has the left lifting property with respect to `p`, or equivalently that `p` has the right lifting property with respect to `i`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sq_has_lift_of_has_lifting_property {f : A ⟶ X} {g : B ⟶ Y} (sq : comm_sq f i p g) [hip : has_lifting_property i p] : sq.has_lift
by apply hip.sq_has_lift
instance
category_theory.sq_has_lift_of_has_lifting_property
category_theory.lifting_properties
src/category_theory/lifting_properties/basic.lean
[ "category_theory.comm_sq" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
op (h : has_lifting_property i p) : has_lifting_property p.op i.op
⟨λ f g sq, begin simp only [comm_sq.has_lift.iff_unop, quiver.hom.unop_op], apply_instance, end⟩
lemma
category_theory.has_lifting_property.op
category_theory.lifting_properties
src/category_theory/lifting_properties/basic.lean
[ "category_theory.comm_sq" ]
[ "quiver.hom.unop_op" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unop {A B X Y : Cᵒᵖ} {i : A ⟶ B} {p : X ⟶ Y} (h : has_lifting_property i p) : has_lifting_property p.unop i.unop
⟨λ f g sq, begin rw comm_sq.has_lift.iff_op, simp only [quiver.hom.op_unop], apply_instance, end⟩
lemma
category_theory.has_lifting_property.unop
category_theory.lifting_properties
src/category_theory/lifting_properties/basic.lean
[ "category_theory.comm_sq" ]
[ "quiver.hom.op_unop" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
iff_op : has_lifting_property i p ↔ has_lifting_property p.op i.op
⟨op, unop⟩
lemma
category_theory.has_lifting_property.iff_op
category_theory.lifting_properties
src/category_theory/lifting_properties/basic.lean
[ "category_theory.comm_sq" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
iff_unop {A B X Y : Cᵒᵖ} (i : A ⟶ B) (p : X ⟶ Y) : has_lifting_property i p ↔ has_lifting_property p.unop i.unop
⟨unop, op⟩
lemma
category_theory.has_lifting_property.iff_unop
category_theory.lifting_properties
src/category_theory/lifting_properties/basic.lean
[ "category_theory.comm_sq" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_left_iso [is_iso i] : has_lifting_property i p
⟨λ f g sq, comm_sq.has_lift.mk' { l := inv i ≫ f, fac_left' := by simp only [is_iso.hom_inv_id_assoc], fac_right' := by simp only [sq.w, assoc, is_iso.inv_hom_id_assoc], }⟩
instance
category_theory.has_lifting_property.of_left_iso
category_theory.lifting_properties
src/category_theory/lifting_properties/basic.lean
[ "category_theory.comm_sq" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_right_iso [is_iso p] : has_lifting_property i p
⟨λ f g sq, comm_sq.has_lift.mk' { l := g ≫ inv p, fac_left' := by simp only [← sq.w_assoc, is_iso.hom_inv_id, comp_id], fac_right' := by simp only [assoc, is_iso.inv_hom_id, comp_id], }⟩
instance
category_theory.has_lifting_property.of_right_iso
category_theory.lifting_properties
src/category_theory/lifting_properties/basic.lean
[ "category_theory.comm_sq" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_comp_left [has_lifting_property i p] [has_lifting_property i' p] : has_lifting_property (i ≫ i') p
⟨λ f g sq, begin have fac := sq.w, rw assoc at fac, exact comm_sq.has_lift.mk' { l := (comm_sq.mk (comm_sq.mk fac).fac_right).lift, fac_left' := by simp only [assoc, comm_sq.fac_left], fac_right' := by simp only [comm_sq.fac_right], }, end⟩
instance
category_theory.has_lifting_property.of_comp_left
category_theory.lifting_properties
src/category_theory/lifting_properties/basic.lean
[ "category_theory.comm_sq" ]
[ "lift" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_comp_right [has_lifting_property i p] [has_lifting_property i p'] : has_lifting_property i (p ≫ p')
⟨λ f g sq, begin have fac := sq.w, rw ← assoc at fac, let sq₂ := (comm_sq.mk ((comm_sq.mk fac).fac_left.symm)).lift, exact comm_sq.has_lift.mk' { l := (comm_sq.mk ((comm_sq.mk fac).fac_left.symm)).lift, fac_left' := by simp only [comm_sq.fac_left], fac_right' := by simp only [comm_sq.fac_right_a...
instance
category_theory.has_lifting_property.of_comp_right
category_theory.lifting_properties
src/category_theory/lifting_properties/basic.lean
[ "category_theory.comm_sq" ]
[ "lift" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_arrow_iso_left {A B A' B' X Y : C} {i : A ⟶ B} {i' : A' ⟶ B'} (e : arrow.mk i ≅ arrow.mk i') (p : X ⟶ Y) [hip : has_lifting_property i p] : has_lifting_property i' p
by { rw arrow.iso_w' e, apply_instance, }
lemma
category_theory.has_lifting_property.of_arrow_iso_left
category_theory.lifting_properties
src/category_theory/lifting_properties/basic.lean
[ "category_theory.comm_sq" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_arrow_iso_right {A B X Y X' Y' : C} (i : A ⟶ B) {p : X ⟶ Y} {p' : X' ⟶ Y'} (e : arrow.mk p ≅ arrow.mk p') [hip : has_lifting_property i p] : has_lifting_property i p'
by { rw arrow.iso_w' e, apply_instance, }
lemma
category_theory.has_lifting_property.of_arrow_iso_right
category_theory.lifting_properties
src/category_theory/lifting_properties/basic.lean
[ "category_theory.comm_sq" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
iff_of_arrow_iso_left {A B A' B' X Y : C} {i : A ⟶ B} {i' : A' ⟶ B'} (e : arrow.mk i ≅ arrow.mk i') (p : X ⟶ Y) : has_lifting_property i p ↔ has_lifting_property i' p
by { split; introI, exacts [of_arrow_iso_left e p, of_arrow_iso_left e.symm p], }
lemma
category_theory.has_lifting_property.iff_of_arrow_iso_left
category_theory.lifting_properties
src/category_theory/lifting_properties/basic.lean
[ "category_theory.comm_sq" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
iff_of_arrow_iso_right {A B X Y X' Y' : C} (i : A ⟶ B) {p : X ⟶ Y} {p' : X' ⟶ Y'} (e : arrow.mk p ≅ arrow.mk p') : has_lifting_property i p ↔ has_lifting_property i p'
by { split; introI, exacts [of_arrow_iso_right i e, of_arrow_iso_right i e.symm], }
lemma
category_theory.has_lifting_property.iff_of_arrow_iso_right
category_theory.lifting_properties
src/category_theory/lifting_properties/basic.lean
[ "category_theory.comm_sq" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bicone | left : bicone | right : bicone | diagram (val : J) : bicone
inductive
category_theory.bicone
category_theory.limits
src/category_theory/limits/bicones.lean
[ "category_theory.limits.cones", "category_theory.fin_category" ]
[]
Given a category `J`, construct a walking `bicone J` by adjoining two elements.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
fin_bicone [fintype J] : fintype (bicone J)
{ elems := [bicone.left, bicone.right].to_finset ∪ finset.image bicone.diagram (fintype.elems J), complete := λ j, by { cases j; simp, exact fintype.complete j, }, }
instance
category_theory.fin_bicone
category_theory.limits
src/category_theory/limits/bicones.lean
[ "category_theory.limits.cones", "category_theory.fin_category" ]
[ "finset.image", "fintype" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bicone_hom : bicone J → bicone J → Type (max u₁ v₁) | left_id : bicone_hom bicone.left bicone.left | right_id : bicone_hom bicone.right bicone.right | left (j : J) : bicone_hom bicone.left (bicone.diagram j) | right (j : J) : bicone_hom bicone.right (bicone.diagram j) | diagram {j k : J} (f : j ⟶ k) : bicone_hom (bico...
inductive
category_theory.bicone_hom
category_theory.limits
src/category_theory/limits/bicones.lean
[ "category_theory.limits.cones", "category_theory.fin_category" ]
[]
The homs for a walking `bicone J`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bicone_hom.decidable_eq {j k : bicone J} : decidable_eq (bicone_hom J j k)
λ f g, by { cases f; cases g; simp; apply_instance }
instance
category_theory.bicone_hom.decidable_eq
category_theory.limits
src/category_theory/limits/bicones.lean
[ "category_theory.limits.cones", "category_theory.fin_category" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bicone_category_struct : category_struct (bicone J)
{ hom := bicone_hom J, id := λ j, bicone.cases_on j bicone_hom.left_id bicone_hom.right_id (λ k, bicone_hom.diagram (𝟙 k)), comp := λ X Y Z f g, by { cases f, exact g, exact g, cases g, exact bicone_hom.left g_k, cases g, exact bicone_hom.right g_k, cases g, exact bicone_hom.diagram (f_f ≫ g_f) }...
instance
category_theory.bicone_category_struct
category_theory.limits
src/category_theory/limits/bicones.lean
[ "category_theory.limits.cones", "category_theory.fin_category" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bicone_category : category (bicone J)
{ id_comp' := λ X Y f, by { cases f; simp }, comp_id' := λ X Y f, by { cases f; simp }, assoc' := λ W X Y Z f g h, by { cases f; cases g; cases h; simp } }
instance
category_theory.bicone_category
category_theory.limits
src/category_theory/limits/bicones.lean
[ "category_theory.limits.cones", "category_theory.fin_category" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bicone_mk {C : Type u₁} [category.{v₁} C] {F : J ⥤ C} (c₁ c₂ : cone F) : bicone J ⥤ C
{ obj := λ X, bicone.cases_on X c₁.X c₂.X (λ j, F.obj j), map := λ X Y f, by { cases f, exact (𝟙 _), exact (𝟙 _), exact c₁.π.app f_1, exact c₂.π.app f_1, exact F.map f_f, }, map_id' := λ X, by { cases X; simp }, map_comp' := λ X Y Z f g, by { cases f, exact (category.id_comp _).symm, exa...
def
category_theory.bicone_mk
category_theory.limits
src/category_theory/limits/bicones.lean
[ "category_theory.limits.cones", "category_theory.fin_category" ]
[]
Given a diagram `F : J ⥤ C` and two `cone F`s, we can join them into a diagram `bicone J ⥤ C`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
fin_bicone_hom [fin_category J] (j k : bicone J) : fintype (j ⟶ k)
begin cases j; cases k, exact { elems := {bicone_hom.left_id}, complete := λ f, by { cases f, simp } }, exact { elems := ∅, complete := λ f, by { cases f } }, exact { elems := {bicone_hom.left k}, complete := λ f, by { cases f, simp } }, exact { elems := ∅, complete := λ f, by { cases f } }, exact { elems :...
instance
category_theory.fin_bicone_hom
category_theory.limits
src/category_theory/limits/bicones.lean
[ "category_theory.limits.cones", "category_theory.fin_category" ]
[ "finset.image", "finset.mem_image", "fintype" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bicone_small_category : small_category (bicone J)
category_theory.bicone_category J
instance
category_theory.bicone_small_category
category_theory.limits
src/category_theory/limits/bicones.lean
[ "category_theory.limits.cones", "category_theory.fin_category" ]
[ "category_theory.bicone_category" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bicone_fin_category [fin_category J] : fin_category (bicone J)
{}
instance
category_theory.bicone_fin_category
category_theory.limits
src/category_theory/limits/bicones.lean
[ "category_theory.limits.cones", "category_theory.fin_category" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_id_left_eq_curry_map {j : J} {k k' : K} {f : k ⟶ k'} : F.map ((𝟙 j, f) : (j, k) ⟶ (j, k')) = ((curry.obj F).obj j).map f
rfl
lemma
category_theory.limits.map_id_left_eq_curry_map
category_theory.limits
src/category_theory/limits/colimit_limit.lean
[ "category_theory.limits.types", "category_theory.functor.currying", "category_theory.limits.functor_category" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_id_right_eq_curry_swap_map {j j' : J} {f : j ⟶ j'} {k : K} : F.map ((f, 𝟙 k) : (j, k) ⟶ (j', k)) = ((curry.obj (swap K J ⋙ F)).obj k).map f
rfl
lemma
category_theory.limits.map_id_right_eq_curry_swap_map
category_theory.limits
src/category_theory/limits/colimit_limit.lean
[ "category_theory.limits.types", "category_theory.functor.currying", "category_theory.limits.functor_category" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
colimit_limit_to_limit_colimit : colimit ((curry.obj (swap K J ⋙ F)) ⋙ lim) ⟶ limit ((curry.obj F) ⋙ colim)
limit.lift ((curry.obj F) ⋙ colim) { X := _, π := { app := λ j, colimit.desc ((curry.obj (swap K J ⋙ F)) ⋙ lim) { X := _, ι := { app := λ k, limit.π ((curry.obj (swap K J ⋙ F)).obj k) j ≫ colimit.ι ((curry.obj F).obj j) k, naturality' := begin dsimp, int...
def
category_theory.limits.colimit_limit_to_limit_colimit
category_theory.limits
src/category_theory/limits/colimit_limit.lean
[ "category_theory.limits.types", "category_theory.functor.currying", "category_theory.limits.functor_category" ]
[ "lim" ]
The universal morphism $\colim_k \lim_j F(j,k) → \lim_j \colim_k F(j, k)$.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ι_colimit_limit_to_limit_colimit_π (j) (k) : colimit.ι _ k ≫ colimit_limit_to_limit_colimit F ≫ limit.π _ j = limit.π ((curry.obj (swap K J ⋙ F)).obj k) j ≫ colimit.ι ((curry.obj F).obj j) k
by { dsimp [colimit_limit_to_limit_colimit], simp, }
lemma
category_theory.limits.ι_colimit_limit_to_limit_colimit_π
category_theory.limits
src/category_theory/limits/colimit_limit.lean
[ "category_theory.limits.types", "category_theory.functor.currying", "category_theory.limits.functor_category" ]
[]
Since `colimit_limit_to_limit_colimit` is a morphism from a colimit to a limit, this lemma characterises it.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ι_colimit_limit_to_limit_colimit_π_apply (F : J × K ⥤ Type v) (j) (k) (f) : limit.π ((curry.obj F) ⋙ colim) j (colimit_limit_to_limit_colimit F (colimit.ι ((curry.obj (swap K J ⋙ F)) ⋙ lim) k f)) = colimit.ι ((curry.obj F).obj j) k (limit.π ((curry.obj (swap K J ⋙ F)).obj k) j f)
by { dsimp [colimit_limit_to_limit_colimit], simp, }
lemma
category_theory.limits.ι_colimit_limit_to_limit_colimit_π_apply
category_theory.limits
src/category_theory/limits/colimit_limit.lean
[ "category_theory.limits.types", "category_theory.functor.currying", "category_theory.limits.functor_category" ]
[ "lim" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
colimit_limit_to_limit_colimit_cone (G : J ⥤ K ⥤ C) [has_limit G] : colim.map_cone (limit.cone G) ⟶ limit.cone (G ⋙ colim)
{ hom := colim.map (limit_iso_swap_comp_lim G).hom ≫ colimit_limit_to_limit_colimit (uncurry.obj G : _) ≫ lim.map (whisker_right (currying.unit_iso.app G).inv colim), w' := λ j, begin ext1 k, simp only [limit_obj_iso_limit_comp_evaluation_hom_π_assoc, iso.app_inv, ι_colimit_limit_to_limit_coli...
def
category_theory.limits.colimit_limit_to_limit_colimit_cone
category_theory.limits
src/category_theory/limits/colimit_limit.lean
[ "category_theory.limits.types", "category_theory.functor.currying", "category_theory.limits.functor_category" ]
[]
The map `colimit_limit_to_limit_colimit` realized as a map of cones.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
limit_auxiliary_cone (c₁ : cone (F ⋙ fst L R)) : cone ((F ⋙ snd L R) ⋙ R)
(cones.postcompose (whisker_left F (comma.nat_trans L R) : _)).obj (L.map_cone c₁)
def
category_theory.comma.limit_auxiliary_cone
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
(Implementation). An auxiliary cone which is useful in order to construct limits in the comma category.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cone_of_preserves [preserves_limit (F ⋙ snd L R) R] (c₁ : cone (F ⋙ fst L R)) {c₂ : cone (F ⋙ snd L R)} (t₂ : is_limit c₂) : cone F
{ X := { left := c₁.X, right := c₂.X, hom := (is_limit_of_preserves R t₂).lift (limit_auxiliary_cone _ c₁) }, π := { app := λ j, { left := c₁.π.app j, right := c₂.π.app j, w' := ((is_limit_of_preserves R t₂).fac (limit_auxiliary_cone F c₁) j).symm }, naturality' := λ j₁ j₂ t, by ext; d...
def
category_theory.comma.cone_of_preserves
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[ "lift" ]
If `R` preserves the appropriate limit, then given a cone for `F ⋙ fst L R : J ⥤ L` and a limit cone for `F ⋙ snd L R : J ⥤ R` we can build a cone for `F` which will turn out to be a limit cone.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cone_of_preserves_is_limit [preserves_limit (F ⋙ snd L R) R] {c₁ : cone (F ⋙ fst L R)} (t₁ : is_limit c₁) {c₂ : cone (F ⋙ snd L R)} (t₂ : is_limit c₂) : is_limit (cone_of_preserves F c₁ t₂)
{ lift := λ s, { left := t₁.lift ((fst L R).map_cone s), right := t₂.lift ((snd L R).map_cone s), w' := (is_limit_of_preserves R t₂).hom_ext $ λ j, begin rw [cone_of_preserves_X_hom, assoc, assoc, (is_limit_of_preserves R t₂).fac, limit_auxiliary_cone_π_app, ←L.map_comp_assoc, t₁.fac, R.map_...
def
category_theory.comma.cone_of_preserves_is_limit
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[ "hom_ext", "lift" ]
Provided that `R` preserves the appropriate limit, then the cone in `cone_of_preserves` is a limit.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
colimit_auxiliary_cocone (c₂ : cocone (F ⋙ snd L R)) : cocone ((F ⋙ fst L R) ⋙ L)
(cocones.precompose (whisker_left F (comma.nat_trans L R) : _)).obj (R.map_cocone c₂)
def
category_theory.comma.colimit_auxiliary_cocone
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
(Implementation). An auxiliary cocone which is useful in order to construct colimits in the comma category.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cocone_of_preserves [preserves_colimit (F ⋙ fst L R) L] {c₁ : cocone (F ⋙ fst L R)} (t₁ : is_colimit c₁) (c₂ : cocone (F ⋙ snd L R)) : cocone F
{ X := { left := c₁.X, right := c₂.X, hom := (is_colimit_of_preserves L t₁).desc (colimit_auxiliary_cocone _ c₂) }, ι := { app := λ j, { left := c₁.ι.app j, right := c₂.ι.app j, w' := ((is_colimit_of_preserves L t₁).fac (colimit_auxiliary_cocone _ c₂) j) }, naturality' := λ j₁ j₂ t, by...
def
category_theory.comma.cocone_of_preserves
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
If `L` preserves the appropriate colimit, then given a colimit cocone for `F ⋙ fst L R : J ⥤ L` and a cocone for `F ⋙ snd L R : J ⥤ R` we can build a cocone for `F` which will turn out to be a colimit cocone.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cocone_of_preserves_is_colimit [preserves_colimit (F ⋙ fst L R) L] {c₁ : cocone (F ⋙ fst L R)} (t₁ : is_colimit c₁) {c₂ : cocone (F ⋙ snd L R)} (t₂ : is_colimit c₂) : is_colimit (cocone_of_preserves F t₁ c₂)
{ desc := λ s, { left := t₁.desc ((fst L R).map_cocone s), right := t₂.desc ((snd L R).map_cocone s), w' := (is_colimit_of_preserves L t₁).hom_ext $ λ j, begin rw [cocone_of_preserves_X_hom, (is_colimit_of_preserves L t₁).fac_assoc, colimit_auxiliary_cocone_ι_app, assoc, ←R.map_comp, t₂.fac,...
def
category_theory.comma.cocone_of_preserves_is_colimit
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[ "hom_ext" ]
Provided that `L` preserves the appropriate colimit, then the cocone in `cocone_of_preserves` is a colimit.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_limit (F : J ⥤ comma L R) [has_limit (F ⋙ fst L R)] [has_limit (F ⋙ snd L R)] [preserves_limit (F ⋙ snd L R) R] : has_limit F
has_limit.mk ⟨_, cone_of_preserves_is_limit _ (limit.is_limit _) (limit.is_limit _)⟩
instance
category_theory.comma.has_limit
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_limits_of_shape [has_limits_of_shape J A] [has_limits_of_shape J B] [preserves_limits_of_shape J R] : has_limits_of_shape J (comma L R)
{}
instance
category_theory.comma.has_limits_of_shape
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_limits [has_limits A] [has_limits B] [preserves_limits R] : has_limits (comma L R)
⟨infer_instance⟩
instance
category_theory.comma.has_limits
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_colimit (F : J ⥤ comma L R) [has_colimit (F ⋙ fst L R)] [has_colimit (F ⋙ snd L R)] [preserves_colimit (F ⋙ fst L R) L] : has_colimit F
has_colimit.mk ⟨_, cocone_of_preserves_is_colimit _ (colimit.is_colimit _) (colimit.is_colimit _)⟩
instance
category_theory.comma.has_colimit
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_colimits_of_shape [has_colimits_of_shape J A] [has_colimits_of_shape J B] [preserves_colimits_of_shape J L] : has_colimits_of_shape J (comma L R)
{}
instance
category_theory.comma.has_colimits_of_shape
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_colimits [has_colimits A] [has_colimits B] [preserves_colimits L] : has_colimits (comma L R)
⟨infer_instance⟩
instance
category_theory.comma.has_colimits
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_limit (F : J ⥤ arrow T) [i₁ : has_limit (F ⋙ left_func)] [i₂ : has_limit (F ⋙ right_func)] : has_limit F
@@comma.has_limit _ _ _ _ _ i₁ i₂ _
instance
category_theory.arrow.has_limit
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_limits_of_shape [has_limits_of_shape J T] : has_limits_of_shape J (arrow T)
{}
instance
category_theory.arrow.has_limits_of_shape
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_limits [has_limits T] : has_limits (arrow T)
⟨infer_instance⟩
instance
category_theory.arrow.has_limits
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_colimit (F : J ⥤ arrow T) [i₁ : has_colimit (F ⋙ left_func)] [i₂ : has_colimit (F ⋙ right_func)] : has_colimit F
@@comma.has_colimit _ _ _ _ _ i₁ i₂ _
instance
category_theory.arrow.has_colimit
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_colimits_of_shape [has_colimits_of_shape J T] : has_colimits_of_shape J (arrow T)
{}
instance
category_theory.arrow.has_colimits_of_shape
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_colimits [has_colimits T] : has_colimits (arrow T)
⟨infer_instance⟩
instance
category_theory.arrow.has_colimits
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_limit [i₁ : has_limit (F ⋙ proj X G)] [i₂ : preserves_limit (F ⋙ proj X G) G] : has_limit F
@@comma.has_limit _ _ _ _ _ _ i₁ i₂
instance
category_theory.structured_arrow.has_limit
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_limits_of_shape [has_limits_of_shape J A] [preserves_limits_of_shape J G] : has_limits_of_shape J (structured_arrow X G)
{}
instance
category_theory.structured_arrow.has_limits_of_shape
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_limits [has_limits A] [preserves_limits G] : has_limits (structured_arrow X G)
⟨infer_instance⟩
instance
category_theory.structured_arrow.has_limits
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
creates_limit [i : preserves_limit (F ⋙ proj X G) G] : creates_limit F (proj X G)
creates_limit_of_reflects_iso $ λ c t, { lifted_cone := @@comma.cone_of_preserves _ _ _ _ _ i punit_cone t, makes_limit := comma.cone_of_preserves_is_limit _ punit_cone_is_limit _, valid_lift := cones.ext (iso.refl _) $ λ j, (id_comp _).symm }
instance
category_theory.structured_arrow.creates_limit
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
creates_limits_of_shape [preserves_limits_of_shape J G] : creates_limits_of_shape J (proj X G)
{}
instance
category_theory.structured_arrow.creates_limits_of_shape
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
creates_limits [preserves_limits G] : creates_limits (proj X G : _)
⟨⟩
instance
category_theory.structured_arrow.creates_limits
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mono_right_of_mono [has_pullbacks A] [preserves_limits_of_shape walking_cospan G] {Y Z : structured_arrow X G} (f : Y ⟶ Z) [mono f] : mono f.right
show mono ((proj X G).map f), from infer_instance
instance
category_theory.structured_arrow.mono_right_of_mono
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mono_iff_mono_right [has_pullbacks A] [preserves_limits_of_shape walking_cospan G] {Y Z : structured_arrow X G} (f : Y ⟶ Z) : mono f ↔ mono f.right
⟨λ h, by exactI infer_instance, λ h, by exactI mono_of_mono_right f⟩
lemma
category_theory.structured_arrow.mono_iff_mono_right
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_colimit [i₁ : has_colimit (F ⋙ proj G X)] [i₂ : preserves_colimit (F ⋙ proj G X) G] : has_colimit F
@@comma.has_colimit _ _ _ _ _ i₁ _ i₂
instance
category_theory.costructured_arrow.has_colimit
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_colimits_of_shape [has_colimits_of_shape J A] [preserves_colimits_of_shape J G] : has_colimits_of_shape J (costructured_arrow G X)
{}
instance
category_theory.costructured_arrow.has_colimits_of_shape
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_colimits [has_colimits A] [preserves_colimits G] : has_colimits (costructured_arrow G X)
⟨infer_instance⟩
instance
category_theory.costructured_arrow.has_colimits
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
creates_colimit [i : preserves_colimit (F ⋙ proj G X) G] : creates_colimit F (proj G X)
creates_colimit_of_reflects_iso $ λ c t, { lifted_cocone := @@comma.cocone_of_preserves _ _ _ _ _ i t punit_cocone, makes_colimit := comma.cocone_of_preserves_is_colimit _ _ punit_cocone_is_colimit, valid_lift := cocones.ext (iso.refl _) $ λ j, comp_id _ }
instance
category_theory.costructured_arrow.creates_colimit
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
creates_colimits_of_shape [preserves_colimits_of_shape J G] : creates_colimits_of_shape J (proj G X)
{}
instance
category_theory.costructured_arrow.creates_colimits_of_shape
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
creates_colimits [preserves_colimits G] : creates_colimits (proj G X : _)
⟨⟩
instance
category_theory.costructured_arrow.creates_colimits
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
epi_left_of_epi [has_pushouts A] [preserves_colimits_of_shape walking_span G] {Y Z : costructured_arrow G X} (f : Y ⟶ Z) [epi f] : epi f.left
show epi ((proj G X).map f), from infer_instance
instance
category_theory.costructured_arrow.epi_left_of_epi
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
epi_iff_epi_left [has_pushouts A] [preserves_colimits_of_shape walking_span G] {Y Z : costructured_arrow G X} (f : Y ⟶ Z) : epi f ↔ epi f.left
⟨λ h, by exactI infer_instance, λ h, by exactI epi_of_epi_left f⟩
lemma
category_theory.costructured_arrow.epi_iff_epi_left
category_theory.limits
src/category_theory/limits/comma.lean
[ "category_theory.arrow", "category_theory.limits.constructions.epi_mono", "category_theory.limits.creates", "category_theory.limits.unit", "category_theory.structured_arrow" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
concrete.to_product_injective_of_is_limit {D : cone F} (hD : is_limit D) : function.injective (λ (x : D.X) (j : J), D.π.app j x)
begin let E := (forget C).map_cone D, let hE : is_limit E := is_limit_of_preserves _ hD, let G := types.limit_cone.{w v} (F ⋙ forget C), let hG := types.limit_cone_is_limit.{w v} (F ⋙ forget C), let T : E.X ≅ G.X := hE.cone_point_unique_up_to_iso hG, change function.injective (T.hom ≫ (λ x j, G.π.app j x)),...
lemma
category_theory.limits.concrete.to_product_injective_of_is_limit
category_theory.limits
src/category_theory/limits/concrete_category.lean
[ "category_theory.limits.preserves.basic", "category_theory.limits.types", "category_theory.limits.shapes.wide_pullbacks", "category_theory.limits.shapes.multiequalizer", "category_theory.concrete_category.basic", "category_theory.limits.shapes.kernels", "tactic.apply_fun" ]
[ "subtype.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
concrete.is_limit_ext {D : cone F} (hD : is_limit D) (x y : D.X) : (∀ j, D.π.app j x = D.π.app j y) → x = y
λ h, concrete.to_product_injective_of_is_limit _ hD (funext h)
lemma
category_theory.limits.concrete.is_limit_ext
category_theory.limits
src/category_theory/limits/concrete_category.lean
[ "category_theory.limits.preserves.basic", "category_theory.limits.types", "category_theory.limits.shapes.wide_pullbacks", "category_theory.limits.shapes.multiequalizer", "category_theory.concrete_category.basic", "category_theory.limits.shapes.kernels", "tactic.apply_fun" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
concrete.limit_ext [has_limit F] (x y : limit F) : (∀ j, limit.π F j x = limit.π F j y) → x = y
concrete.is_limit_ext F (limit.is_limit _) _ _
lemma
category_theory.limits.concrete.limit_ext
category_theory.limits
src/category_theory/limits/concrete_category.lean
[ "category_theory.limits.preserves.basic", "category_theory.limits.types", "category_theory.limits.shapes.wide_pullbacks", "category_theory.limits.shapes.multiequalizer", "category_theory.concrete_category.basic", "category_theory.limits.shapes.kernels", "tactic.apply_fun" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
concrete.wide_pullback_ext {B : C} {ι : Type w} {X : ι → C} (f : Π j : ι, X j ⟶ B) [has_wide_pullback B X f] [preserves_limit (wide_cospan B X f) (forget C)] (x y : wide_pullback B X f) (h₀ : base f x = base f y) (h : ∀ j, π f j x = π f j y) : x = y
begin apply concrete.limit_ext, rintro (_|j), { exact h₀ }, { apply h } end
lemma
category_theory.limits.concrete.wide_pullback_ext
category_theory.limits
src/category_theory/limits/concrete_category.lean
[ "category_theory.limits.preserves.basic", "category_theory.limits.types", "category_theory.limits.shapes.wide_pullbacks", "category_theory.limits.shapes.multiequalizer", "category_theory.concrete_category.basic", "category_theory.limits.shapes.kernels", "tactic.apply_fun" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
concrete.wide_pullback_ext' {B : C} {ι : Type w} [nonempty ι] {X : ι → C} (f : Π j : ι, X j ⟶ B) [has_wide_pullback.{w} B X f] [preserves_limit (wide_cospan B X f) (forget C)] (x y : wide_pullback B X f) (h : ∀ j, π f j x = π f j y) : x = y
begin apply concrete.wide_pullback_ext _ _ _ _ h, inhabit ι, simp only [← π_arrow f (arbitrary _), comp_apply, h], end
lemma
category_theory.limits.concrete.wide_pullback_ext'
category_theory.limits
src/category_theory/limits/concrete_category.lean
[ "category_theory.limits.preserves.basic", "category_theory.limits.types", "category_theory.limits.shapes.wide_pullbacks", "category_theory.limits.shapes.multiequalizer", "category_theory.concrete_category.basic", "category_theory.limits.shapes.kernels", "tactic.apply_fun" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
concrete.multiequalizer_ext {I : multicospan_index.{w} C} [has_multiequalizer I] [preserves_limit I.multicospan (forget C)] (x y : multiequalizer I) (h : ∀ (t : I.L), multiequalizer.ι I t x = multiequalizer.ι I t y) : x = y
begin apply concrete.limit_ext, rintros (a|b), { apply h }, { rw [← limit.w I.multicospan (walking_multicospan.hom.fst b), comp_apply, comp_apply, h] } end
lemma
category_theory.limits.concrete.multiequalizer_ext
category_theory.limits
src/category_theory/limits/concrete_category.lean
[ "category_theory.limits.preserves.basic", "category_theory.limits.types", "category_theory.limits.shapes.wide_pullbacks", "category_theory.limits.shapes.multiequalizer", "category_theory.concrete_category.basic", "category_theory.limits.shapes.kernels", "tactic.apply_fun" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
concrete.multiequalizer_equiv_aux (I : multicospan_index C) : (I.multicospan ⋙ (forget C)).sections ≃ { x : Π (i : I.L), I.left i // ∀ (i : I.R), I.fst i (x _) = I.snd i (x _) }
{ to_fun := λ x, ⟨λ i, x.1 (walking_multicospan.left _), λ i, begin have a := x.2 (walking_multicospan.hom.fst i), have b := x.2 (walking_multicospan.hom.snd i), rw ← b at a, exact a, end⟩, inv_fun := λ x, { val := λ j, match j with | walking_multicospan.left a := x.1 _ | walking_multi...
def
category_theory.limits.concrete.multiequalizer_equiv_aux
category_theory.limits
src/category_theory/limits/concrete_category.lean
[ "category_theory.limits.preserves.basic", "category_theory.limits.types", "category_theory.limits.shapes.wide_pullbacks", "category_theory.limits.shapes.multiequalizer", "category_theory.concrete_category.basic", "category_theory.limits.shapes.kernels", "tactic.apply_fun" ]
[ "inv_fun" ]
An auxiliary equivalence to be used in `multiequalizer_equiv` below.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
concrete.multiequalizer_equiv (I : multicospan_index.{w} C) [has_multiequalizer I] [preserves_limit I.multicospan (forget C)] : (multiequalizer I : C) ≃ { x : Π (i : I.L), I.left i // ∀ (i : I.R), I.fst i (x _) = I.snd i (x _) }
let h1 := (limit.is_limit I.multicospan), h2 := (is_limit_of_preserves (forget C) h1), E := h2.cone_point_unique_up_to_iso (types.limit_cone_is_limit _) in equiv.trans E.to_equiv (concrete.multiequalizer_equiv_aux I)
def
category_theory.limits.concrete.multiequalizer_equiv
category_theory.limits
src/category_theory/limits/concrete_category.lean
[ "category_theory.limits.preserves.basic", "category_theory.limits.types", "category_theory.limits.shapes.wide_pullbacks", "category_theory.limits.shapes.multiequalizer", "category_theory.concrete_category.basic", "category_theory.limits.shapes.kernels", "tactic.apply_fun" ]
[ "equiv.trans" ]
The equivalence between the noncomputable multiequalizer and and the concrete multiequalizer.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
concrete.multiequalizer_equiv_apply (I : multicospan_index.{w} C) [has_multiequalizer I] [preserves_limit I.multicospan (forget C)] (x : multiequalizer I) (i : I.L) : ((concrete.multiequalizer_equiv I) x : Π (i : I.L), I.left i) i = multiequalizer.ι I i x
rfl
lemma
category_theory.limits.concrete.multiequalizer_equiv_apply
category_theory.limits
src/category_theory/limits/concrete_category.lean
[ "category_theory.limits.preserves.basic", "category_theory.limits.types", "category_theory.limits.shapes.wide_pullbacks", "category_theory.limits.shapes.multiequalizer", "category_theory.concrete_category.basic", "category_theory.limits.shapes.kernels", "tactic.apply_fun" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cokernel_funext {C : Type*} [category C] [has_zero_morphisms C] [concrete_category C] {M N K : C} {f : M ⟶ N} [has_cokernel f] {g h : cokernel f ⟶ K} (w : ∀ (n : N), g (cokernel.π f n) = h (cokernel.π f n)) : g = h
begin apply coequalizer.hom_ext, apply concrete_category.hom_ext _ _, simpa using w, end
lemma
category_theory.limits.cokernel_funext
category_theory.limits
src/category_theory/limits/concrete_category.lean
[ "category_theory.limits.preserves.basic", "category_theory.limits.types", "category_theory.limits.shapes.wide_pullbacks", "category_theory.limits.shapes.multiequalizer", "category_theory.concrete_category.basic", "category_theory.limits.shapes.kernels", "tactic.apply_fun" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
concrete.from_union_surjective_of_is_colimit {D : cocone F} (hD : is_colimit D) : let ff : (Σ (j : J), F.obj j) → D.X
λ a, D.ι.app a.1 a.2 in function.surjective ff := begin intro ff, let E := (forget C).map_cocone D, let hE : is_colimit E := is_colimit_of_preserves _ hD, let G := types.colimit_cocone.{v v} (F ⋙ forget C), let hG := types.colimit_cocone_is_colimit.{v v} (F ⋙ forget C), let T : E ≅ G := hE.unique_up_to_iso ...
lemma
category_theory.limits.concrete.from_union_surjective_of_is_colimit
category_theory.limits
src/category_theory/limits/concrete_category.lean
[ "category_theory.limits.preserves.basic", "category_theory.limits.types", "category_theory.limits.shapes.wide_pullbacks", "category_theory.limits.shapes.multiequalizer", "category_theory.concrete_category.basic", "category_theory.limits.shapes.kernels", "tactic.apply_fun" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
concrete.is_colimit_exists_rep {D : cocone F} (hD : is_colimit D) (x : D.X) : ∃ (j : J) (y : F.obj j), D.ι.app j y = x
begin obtain ⟨a, rfl⟩ := concrete.from_union_surjective_of_is_colimit F hD x, exact ⟨a.1, a.2, rfl⟩, end
lemma
category_theory.limits.concrete.is_colimit_exists_rep
category_theory.limits
src/category_theory/limits/concrete_category.lean
[ "category_theory.limits.preserves.basic", "category_theory.limits.types", "category_theory.limits.shapes.wide_pullbacks", "category_theory.limits.shapes.multiequalizer", "category_theory.concrete_category.basic", "category_theory.limits.shapes.kernels", "tactic.apply_fun" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
concrete.colimit_exists_rep [has_colimit F] (x : colimit F) : ∃ (j : J) (y : F.obj j), colimit.ι F j y = x
concrete.is_colimit_exists_rep F (colimit.is_colimit _) x
lemma
category_theory.limits.concrete.colimit_exists_rep
category_theory.limits
src/category_theory/limits/concrete_category.lean
[ "category_theory.limits.preserves.basic", "category_theory.limits.types", "category_theory.limits.shapes.wide_pullbacks", "category_theory.limits.shapes.multiequalizer", "category_theory.concrete_category.basic", "category_theory.limits.shapes.kernels", "tactic.apply_fun" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
concrete.is_colimit_rep_eq_of_exists {D : cocone F} {i j : J} (hD : is_colimit D) (x : F.obj i) (y : F.obj j) (h : ∃ k (f : i ⟶ k) (g : j ⟶ k), F.map f x = F.map g y) : D.ι.app i x = D.ι.app j y
begin let E := (forget C).map_cocone D, let hE : is_colimit E := is_colimit_of_preserves _ hD, let G := types.colimit_cocone.{v v} (F ⋙ forget C), let hG := types.colimit_cocone_is_colimit.{v v} (F ⋙ forget C), let T : E ≅ G := hE.unique_up_to_iso hG, let TX : E.X ≅ G.X := (cocones.forget _).map_iso T, ap...
lemma
category_theory.limits.concrete.is_colimit_rep_eq_of_exists
category_theory.limits
src/category_theory/limits/concrete_category.lean
[ "category_theory.limits.preserves.basic", "category_theory.limits.types", "category_theory.limits.shapes.wide_pullbacks", "category_theory.limits.shapes.multiequalizer", "category_theory.concrete_category.basic", "category_theory.limits.shapes.kernels", "tactic.apply_fun" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
concrete.colimit_rep_eq_of_exists [has_colimit F] {i j : J} (x : F.obj i) (y : F.obj j) (h : ∃ k (f : i ⟶ k) (g : j ⟶ k), F.map f x = F.map g y) : colimit.ι F i x = colimit.ι F j y
concrete.is_colimit_rep_eq_of_exists F (colimit.is_colimit _) x y h
lemma
category_theory.limits.concrete.colimit_rep_eq_of_exists
category_theory.limits
src/category_theory/limits/concrete_category.lean
[ "category_theory.limits.preserves.basic", "category_theory.limits.types", "category_theory.limits.shapes.wide_pullbacks", "category_theory.limits.shapes.multiequalizer", "category_theory.concrete_category.basic", "category_theory.limits.shapes.kernels", "tactic.apply_fun" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
concrete.is_colimit_exists_of_rep_eq {D : cocone F} {i j : J} (hD : is_colimit D) (x : F.obj i) (y : F.obj j) (h : D.ι.app _ x = D.ι.app _ y) : ∃ k (f : i ⟶ k) (g : j ⟶ k), F.map f x = F.map g y
begin let E := (forget C).map_cocone D, let hE : is_colimit E := is_colimit_of_preserves _ hD, let G := types.colimit_cocone.{v v} (F ⋙ forget C), let hG := types.colimit_cocone_is_colimit.{v v} (F ⋙ forget C), let T : E ≅ G := hE.unique_up_to_iso hG, let TX : E.X ≅ G.X := (cocones.forget _).map_iso T, ap...
lemma
category_theory.limits.concrete.is_colimit_exists_of_rep_eq
category_theory.limits
src/category_theory/limits/concrete_category.lean
[ "category_theory.limits.preserves.basic", "category_theory.limits.types", "category_theory.limits.shapes.wide_pullbacks", "category_theory.limits.shapes.multiequalizer", "category_theory.concrete_category.basic", "category_theory.limits.shapes.kernels", "tactic.apply_fun" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
concrete.is_colimit_rep_eq_iff_exists {D : cocone F} {i j : J} (hD : is_colimit D) (x : F.obj i) (y : F.obj j) : D.ι.app i x = D.ι.app j y ↔ ∃ k (f : i ⟶ k) (g : j ⟶ k), F.map f x = F.map g y
⟨concrete.is_colimit_exists_of_rep_eq _ hD _ _, concrete.is_colimit_rep_eq_of_exists _ hD _ _⟩
theorem
category_theory.limits.concrete.is_colimit_rep_eq_iff_exists
category_theory.limits
src/category_theory/limits/concrete_category.lean
[ "category_theory.limits.preserves.basic", "category_theory.limits.types", "category_theory.limits.shapes.wide_pullbacks", "category_theory.limits.shapes.multiequalizer", "category_theory.concrete_category.basic", "category_theory.limits.shapes.kernels", "tactic.apply_fun" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
concrete.colimit_exists_of_rep_eq [has_colimit F] {i j : J} (x : F.obj i) (y : F.obj j) (h : colimit.ι F _ x = colimit.ι F _ y) : ∃ k (f : i ⟶ k) (g : j ⟶ k), F.map f x = F.map g y
concrete.is_colimit_exists_of_rep_eq F (colimit.is_colimit _) x y h
lemma
category_theory.limits.concrete.colimit_exists_of_rep_eq
category_theory.limits
src/category_theory/limits/concrete_category.lean
[ "category_theory.limits.preserves.basic", "category_theory.limits.types", "category_theory.limits.shapes.wide_pullbacks", "category_theory.limits.shapes.multiequalizer", "category_theory.concrete_category.basic", "category_theory.limits.shapes.kernels", "tactic.apply_fun" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
concrete.colimit_rep_eq_iff_exists [has_colimit F] {i j : J} (x : F.obj i) (y : F.obj j) : colimit.ι F i x = colimit.ι F j y ↔ ∃ k (f : i ⟶ k) (g : j ⟶ k), F.map f x = F.map g y
⟨concrete.colimit_exists_of_rep_eq _ _ _, concrete.colimit_rep_eq_of_exists _ _ _⟩
theorem
category_theory.limits.concrete.colimit_rep_eq_iff_exists
category_theory.limits
src/category_theory/limits/concrete_category.lean
[ "category_theory.limits.preserves.basic", "category_theory.limits.types", "category_theory.limits.shapes.wide_pullbacks", "category_theory.limits.shapes.multiequalizer", "category_theory.concrete_category.basic", "category_theory.limits.shapes.kernels", "tactic.apply_fun" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
concrete.wide_pushout_exists_rep {B : C} {α : Type*} {X : α → C} (f : Π j : α, B ⟶ X j) [has_wide_pushout.{v} B X f] [preserves_colimit (wide_span B X f) (forget C)] (x : wide_pushout B X f) : (∃ y : B, head f y = x) ∨ (∃ (i : α) (y : X i), ι f i y = x)
begin obtain ⟨_ | j, y, rfl⟩ := concrete.colimit_exists_rep _ x, { use y }, { right, use [j,y] } end
lemma
category_theory.limits.concrete.wide_pushout_exists_rep
category_theory.limits
src/category_theory/limits/concrete_category.lean
[ "category_theory.limits.preserves.basic", "category_theory.limits.types", "category_theory.limits.shapes.wide_pullbacks", "category_theory.limits.shapes.multiequalizer", "category_theory.concrete_category.basic", "category_theory.limits.shapes.kernels", "tactic.apply_fun" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
concrete.wide_pushout_exists_rep' {B : C} {α : Type*} [nonempty α] {X : α → C} (f : Π j : α, B ⟶ X j) [has_wide_pushout.{v} B X f] [preserves_colimit (wide_span B X f) (forget C)] (x : wide_pushout B X f) : ∃ (i : α) (y : X i), ι f i y = x
begin rcases concrete.wide_pushout_exists_rep f x with ⟨y, rfl⟩ | ⟨i, y, rfl⟩, { inhabit α, use [arbitrary _, f _ y], simp only [← arrow_ι _ (arbitrary α), comp_apply] }, { use [i,y] } end
lemma
category_theory.limits.concrete.wide_pushout_exists_rep'
category_theory.limits
src/category_theory/limits/concrete_category.lean
[ "category_theory.limits.preserves.basic", "category_theory.limits.types", "category_theory.limits.shapes.wide_pullbacks", "category_theory.limits.shapes.multiequalizer", "category_theory.concrete_category.basic", "category_theory.limits.shapes.kernels", "tactic.apply_fun" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cones : Cᵒᵖ ⥤ Type (max u₁ v₃)
(const J).op ⋙ yoneda.obj F
def
category_theory.functor.cones
category_theory.limits
src/category_theory/limits/cones.lean
[ "category_theory.functor.const", "category_theory.discrete_category", "category_theory.yoneda", "category_theory.functor.reflects_isomorphisms" ]
[]
`F.cones` is the functor assigning to an object `X` the type of natural transformations from the constant functor with value `X` to `F`. An object representing this functor is a limit of `F`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cocones : C ⥤ Type (max u₁ v₃)
const J ⋙ coyoneda.obj (op F)
def
category_theory.functor.cocones
category_theory.limits
src/category_theory/limits/cones.lean
[ "category_theory.functor.const", "category_theory.discrete_category", "category_theory.yoneda", "category_theory.functor.reflects_isomorphisms" ]
[]
`F.cocones` is the functor assigning to an object `X` the type of natural transformations from `F` to the constant functor with value `X`. An object corepresenting this functor is a colimit of `F`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cones : (J ⥤ C) ⥤ (Cᵒᵖ ⥤ Type (max u₁ v₃))
{ obj := functor.cones, map := λ F G f, whisker_left (const J).op (yoneda.map f) }
def
category_theory.cones
category_theory.limits
src/category_theory/limits/cones.lean
[ "category_theory.functor.const", "category_theory.discrete_category", "category_theory.yoneda", "category_theory.functor.reflects_isomorphisms" ]
[]
Functorially associated to each functor `J ⥤ C`, we have the `C`-presheaf consisting of cones with a given cone point.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cocones : (J ⥤ C)ᵒᵖ ⥤ (C ⥤ Type (max u₁ v₃))
{ obj := λ F, functor.cocones (unop F), map := λ F G f, whisker_left (const J) (coyoneda.map f) }
def
category_theory.cocones
category_theory.limits
src/category_theory/limits/cones.lean
[ "category_theory.functor.const", "category_theory.discrete_category", "category_theory.yoneda", "category_theory.functor.reflects_isomorphisms" ]
[]
Contravariantly associated to each functor `J ⥤ C`, we have the `C`-copresheaf consisting of cocones with a given cocone point.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cone (F : J ⥤ C)
(X : C) (π : (const J).obj X ⟶ F)
structure
category_theory.limits.cone
category_theory.limits
src/category_theory/limits/cones.lean
[ "category_theory.functor.const", "category_theory.discrete_category", "category_theory.yoneda", "category_theory.functor.reflects_isomorphisms" ]
[]
A `c : cone F` is: * an object `c.X` and * a natural transformation `c.π : c.X ⟶ F` from the constant `c.X` functor to `F`. `cone F` is equivalent, via `cone.equiv` below, to `Σ X, F.cones.obj X`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inhabited_cone (F : discrete punit ⥤ C) : inhabited (cone F)
⟨{ X := F.obj ⟨⟨⟩⟩, π := { app := λ ⟨⟨⟩⟩, 𝟙 _, }, }⟩
instance
category_theory.limits.inhabited_cone
category_theory.limits
src/category_theory/limits/cones.lean
[ "category_theory.functor.const", "category_theory.discrete_category", "category_theory.yoneda", "category_theory.functor.reflects_isomorphisms" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cone.w {F : J ⥤ C} (c : cone F) {j j' : J} (f : j ⟶ j') : c.π.app j ≫ F.map f = c.π.app j'
by { rw ← c.π.naturality f, apply id_comp }
lemma
category_theory.limits.cone.w
category_theory.limits
src/category_theory/limits/cones.lean
[ "category_theory.functor.const", "category_theory.discrete_category", "category_theory.yoneda", "category_theory.functor.reflects_isomorphisms" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cocone (F : J ⥤ C)
(X : C) (ι : F ⟶ (const J).obj X)
structure
category_theory.limits.cocone
category_theory.limits
src/category_theory/limits/cones.lean
[ "category_theory.functor.const", "category_theory.discrete_category", "category_theory.yoneda", "category_theory.functor.reflects_isomorphisms" ]
[]
A `c : cocone F` is * an object `c.X` and * a natural transformation `c.ι : F ⟶ c.X` from `F` to the constant `c.X` functor. `cocone F` is equivalent, via `cone.equiv` below, to `Σ X, F.cocones.obj X`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inhabited_cocone (F : discrete punit ⥤ C) : inhabited (cocone F)
⟨{ X := F.obj ⟨⟨⟩⟩, ι := { app := λ ⟨⟨⟩⟩, 𝟙 _, }, }⟩
instance
category_theory.limits.inhabited_cocone
category_theory.limits
src/category_theory/limits/cones.lean
[ "category_theory.functor.const", "category_theory.discrete_category", "category_theory.yoneda", "category_theory.functor.reflects_isomorphisms" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cocone.w {F : J ⥤ C} (c : cocone F) {j j' : J} (f : j ⟶ j') : F.map f ≫ c.ι.app j' = c.ι.app j
by { rw c.ι.naturality f, apply comp_id }
lemma
category_theory.limits.cocone.w
category_theory.limits
src/category_theory/limits/cones.lean
[ "category_theory.functor.const", "category_theory.discrete_category", "category_theory.yoneda", "category_theory.functor.reflects_isomorphisms" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equiv (F : J ⥤ C) : cone F ≅ Σ X, F.cones.obj X
{ hom := λ c, ⟨op c.X, c.π⟩, inv := λ c, { X := c.1.unop, π := c.2 }, hom_inv_id' := by { ext1, cases x, refl }, inv_hom_id' := by { ext1, cases x, refl } }
def
category_theory.limits.cone.equiv
category_theory.limits
src/category_theory/limits/cones.lean
[ "category_theory.functor.const", "category_theory.discrete_category", "category_theory.yoneda", "category_theory.functor.reflects_isomorphisms" ]
[ "equiv" ]
The isomorphism between a cone on `F` and an element of the functor `F.cones`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
extensions (c : cone F) : yoneda.obj c.X ⋙ ulift_functor.{u₁} ⟶ F.cones
{ app := λ X f, (const J).map f.down ≫ c.π }
def
category_theory.limits.cone.extensions
category_theory.limits
src/category_theory/limits/cones.lean
[ "category_theory.functor.const", "category_theory.discrete_category", "category_theory.yoneda", "category_theory.functor.reflects_isomorphisms" ]
[]
A map to the vertex of a cone naturally induces a cone by composition.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83