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binary_bicone.inl_cokernel_cofork_π : (binary_bicone.inl_cokernel_cofork c).π = c.snd
rfl
lemma
category_theory.limits.binary_bicone.inl_cokernel_cofork_π
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
binary_bicone.inr_cokernel_cofork : cokernel_cofork c.inr
cokernel_cofork.of_π c.fst c.inr_fst
def
category_theory.limits.binary_bicone.inr_cokernel_cofork
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
A cokernel cofork for the cokernel of `binary_bicone.inr`. It consists of the morphism `binary_bicone.fst`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
binary_bicone.inr_cokernel_cofork_π : (binary_bicone.inr_cokernel_cofork c).π = c.fst
rfl
lemma
category_theory.limits.binary_bicone.inr_cokernel_cofork_π
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
binary_bicone.is_limit_fst_kernel_fork (i : is_limit c.to_cone) : is_limit c.fst_kernel_fork
fork.is_limit.mk' _ $ λ s, ⟨s.ι ≫ c.snd, by apply binary_fan.is_limit.hom_ext i; simp, λ m hm, by simp [← hm]⟩
def
category_theory.limits.binary_bicone.is_limit_fst_kernel_fork
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
The fork defined in `binary_bicone.fst_kernel_fork` is indeed a kernel.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
binary_bicone.is_limit_snd_kernel_fork (i : is_limit c.to_cone) : is_limit c.snd_kernel_fork
fork.is_limit.mk' _ $ λ s, ⟨s.ι ≫ c.fst, by apply binary_fan.is_limit.hom_ext i; simp, λ m hm, by simp [← hm]⟩
def
category_theory.limits.binary_bicone.is_limit_snd_kernel_fork
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
The fork defined in `binary_bicone.snd_kernel_fork` is indeed a kernel.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
binary_bicone.is_colimit_inl_cokernel_cofork (i : is_colimit c.to_cocone) : is_colimit c.inl_cokernel_cofork
cofork.is_colimit.mk' _ $ λ s, ⟨c.inr ≫ s.π, by apply binary_cofan.is_colimit.hom_ext i; simp, λ m hm, by simp [← hm]⟩
def
category_theory.limits.binary_bicone.is_colimit_inl_cokernel_cofork
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
The cofork defined in `binary_bicone.inl_cokernel_cofork` is indeed a cokernel.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
binary_bicone.is_colimit_inr_cokernel_cofork (i : is_colimit c.to_cocone) : is_colimit c.inr_cokernel_cofork
cofork.is_colimit.mk' _ $ λ s, ⟨c.inl ≫ s.π, by apply binary_cofan.is_colimit.hom_ext i; simp, λ m hm, by simp [← hm]⟩
def
category_theory.limits.binary_bicone.is_colimit_inr_cokernel_cofork
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
The cofork defined in `binary_bicone.inr_cokernel_cofork` is indeed a cokernel.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
biprod.fst_kernel_fork : kernel_fork (biprod.fst : X ⊞ Y ⟶ X)
binary_bicone.fst_kernel_fork _
def
category_theory.limits.biprod.fst_kernel_fork
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
A kernel fork for the kernel of `biprod.fst`. It consists of the morphism `biprod.inr`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
biprod.fst_kernel_fork_ι : fork.ι (biprod.fst_kernel_fork X Y) = biprod.inr
rfl
lemma
category_theory.limits.biprod.fst_kernel_fork_ι
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
biprod.is_kernel_fst_kernel_fork : is_limit (biprod.fst_kernel_fork X Y)
binary_bicone.is_limit_fst_kernel_fork (binary_biproduct.is_limit _ _)
def
category_theory.limits.biprod.is_kernel_fst_kernel_fork
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
The fork `biprod.fst_kernel_fork` is indeed a limit.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
biprod.snd_kernel_fork : kernel_fork (biprod.snd : X ⊞ Y ⟶ Y)
binary_bicone.snd_kernel_fork _
def
category_theory.limits.biprod.snd_kernel_fork
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
A kernel fork for the kernel of `biprod.snd`. It consists of the morphism `biprod.inl`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
biprod.snd_kernel_fork_ι : fork.ι (biprod.snd_kernel_fork X Y) = biprod.inl
rfl
lemma
category_theory.limits.biprod.snd_kernel_fork_ι
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
biprod.is_kernel_snd_kernel_fork : is_limit (biprod.snd_kernel_fork X Y)
binary_bicone.is_limit_snd_kernel_fork (binary_biproduct.is_limit _ _)
def
category_theory.limits.biprod.is_kernel_snd_kernel_fork
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
The fork `biprod.snd_kernel_fork` is indeed a limit.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
biprod.inl_cokernel_cofork : cokernel_cofork (biprod.inl : X ⟶ X ⊞ Y)
binary_bicone.inl_cokernel_cofork _
def
category_theory.limits.biprod.inl_cokernel_cofork
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
A cokernel cofork for the cokernel of `biprod.inl`. It consists of the morphism `biprod.snd`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
biprod.inl_cokernel_cofork_π : cofork.π (biprod.inl_cokernel_cofork X Y) = biprod.snd
rfl
lemma
category_theory.limits.biprod.inl_cokernel_cofork_π
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
biprod.is_cokernel_inl_cokernel_fork : is_colimit (biprod.inl_cokernel_cofork X Y)
binary_bicone.is_colimit_inl_cokernel_cofork (binary_biproduct.is_colimit _ _)
def
category_theory.limits.biprod.is_cokernel_inl_cokernel_fork
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
The cofork `biprod.inl_cokernel_fork` is indeed a colimit.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
biprod.inr_cokernel_cofork : cokernel_cofork (biprod.inr : Y ⟶ X ⊞ Y)
binary_bicone.inr_cokernel_cofork _
def
category_theory.limits.biprod.inr_cokernel_cofork
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
A cokernel cofork for the cokernel of `biprod.inr`. It consists of the morphism `biprod.fst`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
biprod.inr_cokernel_cofork_π : cofork.π (biprod.inr_cokernel_cofork X Y) = biprod.fst
rfl
lemma
category_theory.limits.biprod.inr_cokernel_cofork_π
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
biprod.is_cokernel_inr_cokernel_fork : is_colimit (biprod.inr_cokernel_cofork X Y)
binary_bicone.is_colimit_inr_cokernel_cofork (binary_biproduct.is_colimit _ _)
def
category_theory.limits.biprod.is_cokernel_inr_cokernel_fork
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
The cofork `biprod.inr_cokernel_fork` is indeed a colimit.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
kernel_biprod_fst_iso : kernel (biprod.fst : X ⊞ Y ⟶ X) ≅ Y
limit.iso_limit_cone ⟨_, biprod.is_kernel_fst_kernel_fork X Y⟩
def
category_theory.limits.kernel_biprod_fst_iso
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
The kernel of `biprod.fst : X ⊞ Y ⟶ X` is `Y`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
kernel_biprod_snd_iso : kernel (biprod.snd : X ⊞ Y ⟶ Y) ≅ X
limit.iso_limit_cone ⟨_, biprod.is_kernel_snd_kernel_fork X Y⟩
def
category_theory.limits.kernel_biprod_snd_iso
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
The kernel of `biprod.snd : X ⊞ Y ⟶ Y` is `X`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cokernel_biprod_inl_iso : cokernel (biprod.inl : X ⟶ X ⊞ Y) ≅ Y
colimit.iso_colimit_cocone ⟨_, biprod.is_cokernel_inl_cokernel_fork X Y⟩
def
category_theory.limits.cokernel_biprod_inl_iso
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
The cokernel of `biprod.inl : X ⟶ X ⊞ Y` is `Y`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cokernel_biprod_inr_iso : cokernel (biprod.inr : Y ⟶ X ⊞ Y) ≅ X
colimit.iso_colimit_cocone ⟨_, biprod.is_cokernel_inr_cokernel_fork X Y⟩
def
category_theory.limits.cokernel_biprod_inr_iso
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
The cokernel of `biprod.inr : Y ⟶ X ⊞ Y` is `X`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
iso_biprod_zero {X Y : C} [has_binary_biproduct X Y] (hY : is_zero Y) : X ≅ X ⊞ Y
{ hom := biprod.inl, inv := biprod.fst, inv_hom_id' := begin apply category_theory.limits.biprod.hom_ext; simp only [category.assoc, biprod.inl_fst, category.comp_id, category.id_comp, biprod.inl_snd, comp_zero], apply hY.eq_of_tgt end }
def
category_theory.limits.iso_biprod_zero
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[ "category_theory.limits.biprod.hom_ext" ]
If `Y` is a zero object, `X ≅ X ⊞ Y` for any `X`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
iso_zero_biprod {X Y : C} [has_binary_biproduct X Y] (hY : is_zero X) : Y ≅ X ⊞ Y
{ hom := biprod.inr, inv := biprod.snd, inv_hom_id' := begin apply category_theory.limits.biprod.hom_ext; simp only [category.assoc, biprod.inr_snd, category.comp_id, category.id_comp, biprod.inr_fst, comp_zero], apply hY.eq_of_tgt end }
def
category_theory.limits.iso_zero_biprod
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[ "category_theory.limits.biprod.hom_ext" ]
If `X` is a zero object, `Y ≅ X ⊞ Y` for any `Y`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
biprod.braiding (P Q : C) : P ⊞ Q ≅ Q ⊞ P
{ hom := biprod.lift biprod.snd biprod.fst, inv := biprod.lift biprod.snd biprod.fst }
def
category_theory.limits.biprod.braiding
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
The braiding isomorphism which swaps a binary biproduct.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
biprod.braiding' (P Q : C) : P ⊞ Q ≅ Q ⊞ P
{ hom := biprod.desc biprod.inr biprod.inl, inv := biprod.desc biprod.inr biprod.inl }
def
category_theory.limits.biprod.braiding'
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
An alternative formula for the braiding isomorphism which swaps a binary biproduct, using the fact that the biproduct is a coproduct.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
biprod.braiding'_eq_braiding {P Q : C} : biprod.braiding' P Q = biprod.braiding P Q
by tidy
lemma
category_theory.limits.biprod.braiding'_eq_braiding
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
biprod.braid_natural {W X Y Z : C} (f : X ⟶ Y) (g : Z ⟶ W) : biprod.map f g ≫ (biprod.braiding _ _).hom = (biprod.braiding _ _).hom ≫ biprod.map g f
by tidy
lemma
category_theory.limits.biprod.braid_natural
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
The braiding isomorphism can be passed through a map by swapping the order.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
biprod.braiding_map_braiding {W X Y Z : C} (f : W ⟶ Y) (g : X ⟶ Z) : (biprod.braiding X W).hom ≫ biprod.map f g ≫ (biprod.braiding Y Z).hom = biprod.map g f
by tidy
lemma
category_theory.limits.biprod.braiding_map_braiding
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
biprod.symmetry' (P Q : C) : biprod.lift biprod.snd biprod.fst ≫ biprod.lift biprod.snd biprod.fst = 𝟙 (P ⊞ Q)
by tidy
lemma
category_theory.limits.biprod.symmetry'
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
biprod.symmetry (P Q : C) : (biprod.braiding P Q).hom ≫ (biprod.braiding Q P).hom = 𝟙 _
by simp
lemma
category_theory.limits.biprod.symmetry
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
The braiding isomorphism is symmetric.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
indecomposable (X : C) : Prop
¬ is_zero X ∧ ∀ Y Z, (X ≅ Y ⊞ Z) → is_zero Y ∨ is_zero Z
def
category_theory.indecomposable
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
An object is indecomposable if it cannot be written as the biproduct of two nonzero objects.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_iso_left_of_is_iso_biprod_map {W X Y Z : C} (f : W ⟶ Y) (g : X ⟶ Z) [is_iso (biprod.map f g)] : is_iso f
⟨⟨biprod.inl ≫ inv (biprod.map f g) ≫ biprod.fst, ⟨begin have t := congr_arg (λ p : W ⊞ X ⟶ W ⊞ X, biprod.inl ≫ p ≫ biprod.fst) (is_iso.hom_inv_id (biprod.map f g)), simp only [category.id_comp, category.assoc, biprod.inl_map_assoc] at t, simp [t], end, begin have t := congr_arg (λ p : Y ⊞ Z...
lemma
category_theory.is_iso_left_of_is_iso_biprod_map
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
If ``` (f 0) (0 g) ``` is invertible, then `f` is invertible.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_iso_right_of_is_iso_biprod_map {W X Y Z : C} (f : W ⟶ Y) (g : X ⟶ Z) [is_iso (biprod.map f g)] : is_iso g
begin letI : is_iso (biprod.map g f) := by { rw [←biprod.braiding_map_braiding], apply_instance, }, exact is_iso_left_of_is_iso_biprod_map g f, end
lemma
category_theory.is_iso_right_of_is_iso_biprod_map
category_theory.limits.shapes
src/category_theory/limits/shapes/biproducts.lean
[ "category_theory.limits.shapes.finite_products", "category_theory.limits.shapes.binary_products", "category_theory.limits.shapes.kernels" ]
[]
If ``` (f 0) (0 g) ``` is invertible, then `g` is invertible.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cone (s : comm_sq f g h i) : pullback_cone h i
pullback_cone.mk _ _ s.w
def
category_theory.comm_sq.cone
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
The (not necessarily limiting) `pullback_cone h i` implicit in the statement that we have `comm_sq f g h i`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cocone (s : comm_sq f g h i) : pushout_cocone f g
pushout_cocone.mk _ _ s.w
def
category_theory.comm_sq.cocone
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
The (not necessarily limiting) `pushout_cocone f g` implicit in the statement that we have `comm_sq f g h i`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cone_fst (s : comm_sq f g h i) : s.cone.fst = f
rfl
lemma
category_theory.comm_sq.cone_fst
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cone_snd (s : comm_sq f g h i) : s.cone.snd = g
rfl
lemma
category_theory.comm_sq.cone_snd
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cocone_inl (s : comm_sq f g h i) : s.cocone.inl = h
rfl
lemma
category_theory.comm_sq.cocone_inl
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cocone_inr (s : comm_sq f g h i) : s.cocone.inr = i
rfl
lemma
category_theory.comm_sq.cocone_inr
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cone_op (p : comm_sq f g h i) : p.cone.op ≅ p.flip.op.cocone
pushout_cocone.ext (iso.refl _) (by tidy) (by tidy)
def
category_theory.comm_sq.cone_op
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
The pushout cocone in the opposite category associated to the cone of a commutative square identifies to the cocone of the flipped commutative square in the opposite category
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cocone_op (p : comm_sq f g h i) : p.cocone.op ≅ p.flip.op.cone
pullback_cone.ext (iso.refl _) (by tidy) (by tidy)
def
category_theory.comm_sq.cocone_op
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
The pullback cone in the opposite category associated to the cocone of a commutative square identifies to the cone of the flipped commutative square in the opposite category
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cone_unop {W X Y Z : Cᵒᵖ} {f : W ⟶ X} {g : W ⟶ Y} {h : X ⟶ Z} {i : Y ⟶ Z} (p : comm_sq f g h i) : p.cone.unop ≅ p.flip.unop.cocone
pushout_cocone.ext (iso.refl _) (by tidy) (by tidy)
def
category_theory.comm_sq.cone_unop
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
The pushout cocone obtained from the pullback cone associated to a commutative square in the opposite category identifies to the cocone associated to the flipped square.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cocone_unop {W X Y Z : Cᵒᵖ} {f : W ⟶ X} {g : W ⟶ Y} {h : X ⟶ Z} {i : Y ⟶ Z} (p : comm_sq f g h i) : p.cocone.unop ≅ p.flip.unop.cone
pullback_cone.ext (iso.refl _) (by tidy) (by tidy)
def
category_theory.comm_sq.cocone_unop
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
The pullback cone obtained from the pushout cone associated to a commutative square in the opposite category identifies to the cone associated to the flipped square.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_pullback {P X Y Z : C} (fst : P ⟶ X) (snd : P ⟶ Y) (f : X ⟶ Z) (g : Y ⟶ Z) extends comm_sq fst snd f g : Prop
(is_limit' : nonempty (is_limit (pullback_cone.mk _ _ w)))
structure
category_theory.is_pullback
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
The proposition that a square ``` P --fst--> X | | snd f | | v v Y ---g---> Z ``` is a pullback square. (Also known as a fibered product or cartesian square.)
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_pushout {Z X Y P : C} (f : Z ⟶ X) (g : Z ⟶ Y) (inl : X ⟶ P) (inr : Y ⟶ P) extends comm_sq f g inl inr : Prop
(is_colimit' : nonempty (is_colimit (pushout_cocone.mk _ _ w)))
structure
category_theory.is_pushout
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
The proposition that a square ``` Z ---f---> X | | g inl | | v v Y --inr--> P ``` is a pushout square. (Also known as a fiber coproduct or cocartesian square.)
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bicartesian_sq {W X Y Z : C} (f : W ⟶ X) (g : W ⟶ Y) (h : X ⟶ Z) (i : Y ⟶ Z) extends is_pullback f g h i, is_pushout f g h i : Prop
structure
category_theory.bicartesian_sq
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
A *bicartesian* square is a commutative square ``` W ---f---> X | | g h | | v v Y ---i---> Z ``` that is both a pullback square and a pushout square.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cone (h : is_pullback fst snd f g) : pullback_cone f g
h.to_comm_sq.cone
def
category_theory.is_pullback.cone
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
The (limiting) `pullback_cone f g` implicit in the statement that we have a `is_pullback fst snd f g`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cone_fst (h : is_pullback fst snd f g) : h.cone.fst = fst
rfl
lemma
category_theory.is_pullback.cone_fst
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cone_snd (h : is_pullback fst snd f g) : h.cone.snd = snd
rfl
lemma
category_theory.is_pullback.cone_snd
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_limit (h : is_pullback fst snd f g) : is_limit h.cone
h.is_limit'.some
def
category_theory.is_pullback.is_limit
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
The cone obtained from `is_pullback fst snd f g` is a limit cone.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_is_limit {c : pullback_cone f g} (h : limits.is_limit c) : is_pullback c.fst c.snd f g
{ w := c.condition, is_limit' := ⟨is_limit.of_iso_limit h (limits.pullback_cone.ext (iso.refl _) (by tidy) (by tidy))⟩, }
lemma
category_theory.is_pullback.of_is_limit
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
If `c` is a limiting pullback cone, then we have a `is_pullback c.fst c.snd f g`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_is_limit' (w : comm_sq fst snd f g) (h : limits.is_limit w.cone) : is_pullback fst snd f g
of_is_limit h
lemma
category_theory.is_pullback.of_is_limit'
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
A variant of `of_is_limit` that is more useful with `apply`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_has_pullback (f : X ⟶ Z) (g : Y ⟶ Z) [has_pullback f g] : is_pullback (pullback.fst : pullback f g ⟶ X) (pullback.snd : pullback f g ⟶ Y) f g
of_is_limit (limit.is_limit (cospan f g))
lemma
category_theory.is_pullback.of_has_pullback
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
The pullback provided by `has_pullback f g` fits into a `is_pullback`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_is_product {c : binary_fan X Y} (h : limits.is_limit c) (t : is_terminal Z) : is_pullback c.fst c.snd (t.from _) (t.from _)
of_is_limit (is_pullback_of_is_terminal_is_product _ _ _ _ t (is_limit.of_iso_limit h (limits.cones.ext (iso.refl c.X) (by rintro ⟨⟨⟩⟩; { dsimp, simp, }))))
lemma
category_theory.is_pullback.of_is_product
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[ "is_pullback_of_is_terminal_is_product" ]
If `c` is a limiting binary product cone, and we have a terminal object, then we have `is_pullback c.fst c.snd 0 0` (where each `0` is the unique morphism to the terminal object).
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_is_product' (h : limits.is_limit (binary_fan.mk fst snd)) (t : is_terminal Z) : is_pullback fst snd (t.from _) (t.from _)
of_is_product h t
lemma
category_theory.is_pullback.of_is_product'
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
A variant of `of_is_product` that is more useful with `apply`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_has_binary_product' [has_binary_product X Y] [has_terminal C] : is_pullback limits.prod.fst limits.prod.snd (terminal.from X) (terminal.from Y)
of_is_product (limit.is_limit _) terminal_is_terminal
lemma
category_theory.is_pullback.of_has_binary_product'
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_has_binary_product [has_binary_product X Y] [has_zero_object C] [has_zero_morphisms C] : is_pullback limits.prod.fst limits.prod.snd (0 : X ⟶ 0) (0 : Y ⟶ 0)
by convert of_is_product (limit.is_limit _) has_zero_object.zero_is_terminal
lemma
category_theory.is_pullback.of_has_binary_product
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
iso_pullback (h : is_pullback fst snd f g) [has_pullback f g] : P ≅ pullback f g
(limit.iso_limit_cone ⟨_, h.is_limit⟩).symm
def
category_theory.is_pullback.iso_pullback
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
Any object at the top left of a pullback square is isomorphic to the pullback provided by the `has_limit` API.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
iso_pullback_hom_fst (h : is_pullback fst snd f g) [has_pullback f g] : h.iso_pullback.hom ≫ pullback.fst = fst
by { dsimp [iso_pullback, cone, comm_sq.cone], simp, }
lemma
category_theory.is_pullback.iso_pullback_hom_fst
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
iso_pullback_hom_snd (h : is_pullback fst snd f g) [has_pullback f g] : h.iso_pullback.hom ≫ pullback.snd = snd
by { dsimp [iso_pullback, cone, comm_sq.cone], simp, }
lemma
category_theory.is_pullback.iso_pullback_hom_snd
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
iso_pullback_inv_fst (h : is_pullback fst snd f g) [has_pullback f g] : h.iso_pullback.inv ≫ fst = pullback.fst
by simp [iso.inv_comp_eq]
lemma
category_theory.is_pullback.iso_pullback_inv_fst
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
iso_pullback_inv_snd (h : is_pullback fst snd f g) [has_pullback f g] : h.iso_pullback.inv ≫ snd = pullback.snd
by simp [iso.inv_comp_eq]
lemma
category_theory.is_pullback.iso_pullback_inv_snd
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_iso_pullback (h : comm_sq fst snd f g) [has_pullback f g] (i : P ≅ pullback f g) (w₁ : i.hom ≫ pullback.fst = fst) (w₂ : i.hom ≫ pullback.snd = snd) : is_pullback fst snd f g
of_is_limit' h (limits.is_limit.of_iso_limit (limit.is_limit _) (@pullback_cone.ext _ _ _ _ _ _ _ (pullback_cone.mk _ _ _) _ i w₁.symm w₂.symm).symm)
lemma
category_theory.is_pullback.of_iso_pullback
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_horiz_is_iso [is_iso fst] [is_iso g] (sq : comm_sq fst snd f g) : is_pullback fst snd f g
of_is_limit' sq begin refine pullback_cone.is_limit.mk _ (λ s, s.fst ≫ inv fst) (by tidy) (λ s, _) (by tidy), simp only [← cancel_mono g, category.assoc, ← sq.w, is_iso.inv_hom_id_assoc, s.condition], end
lemma
category_theory.is_pullback.of_horiz_is_iso
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cocone (h : is_pushout f g inl inr) : pushout_cocone f g
h.to_comm_sq.cocone
def
category_theory.is_pushout.cocone
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
The (colimiting) `pushout_cocone f g` implicit in the statement that we have a `is_pushout f g inl inr`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cocone_inl (h : is_pushout f g inl inr) : h.cocone.inl = inl
rfl
lemma
category_theory.is_pushout.cocone_inl
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cocone_inr (h : is_pushout f g inl inr) : h.cocone.inr = inr
rfl
lemma
category_theory.is_pushout.cocone_inr
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_colimit (h : is_pushout f g inl inr) : is_colimit h.cocone
h.is_colimit'.some
def
category_theory.is_pushout.is_colimit
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
The cocone obtained from `is_pushout f g inl inr` is a colimit cocone.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_is_colimit {c : pushout_cocone f g} (h : limits.is_colimit c) : is_pushout f g c.inl c.inr
{ w := c.condition, is_colimit' := ⟨is_colimit.of_iso_colimit h (limits.pushout_cocone.ext (iso.refl _) (by tidy) (by tidy))⟩, }
lemma
category_theory.is_pushout.of_is_colimit
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
If `c` is a colimiting pushout cocone, then we have a `is_pushout f g c.inl c.inr`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_is_colimit' (w : comm_sq f g inl inr) (h : limits.is_colimit w.cocone) : is_pushout f g inl inr
of_is_colimit h
lemma
category_theory.is_pushout.of_is_colimit'
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
A variant of `of_is_colimit` that is more useful with `apply`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_has_pushout (f : Z ⟶ X) (g : Z ⟶ Y) [has_pushout f g] : is_pushout f g (pushout.inl : X ⟶ pushout f g) (pushout.inr : Y ⟶ pushout f g)
of_is_colimit (colimit.is_colimit (span f g))
lemma
category_theory.is_pushout.of_has_pushout
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
The pushout provided by `has_pushout f g` fits into a `is_pushout`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_is_coproduct {c : binary_cofan X Y} (h : limits.is_colimit c) (t : is_initial Z) : is_pushout (t.to _) (t.to _) c.inl c.inr
of_is_colimit (is_pushout_of_is_initial_is_coproduct _ _ _ _ t (is_colimit.of_iso_colimit h (limits.cocones.ext (iso.refl c.X) (by rintro ⟨⟨⟩⟩; { dsimp, simp, }))))
lemma
category_theory.is_pushout.of_is_coproduct
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[ "is_pushout_of_is_initial_is_coproduct" ]
If `c` is a colimiting binary coproduct cocone, and we have an initial object, then we have `is_pushout 0 0 c.inl c.inr` (where each `0` is the unique morphism from the initial object).
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_is_coproduct' (h : limits.is_colimit (binary_cofan.mk inl inr)) (t : is_initial Z) : is_pushout (t.to _) (t.to _) inl inr
of_is_coproduct h t
lemma
category_theory.is_pushout.of_is_coproduct'
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
A variant of `of_is_coproduct` that is more useful with `apply`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_has_binary_coproduct' [has_binary_coproduct X Y] [has_initial C] : is_pushout (initial.to _) (initial.to _) (coprod.inl : X ⟶ _) (coprod.inr : Y ⟶ _)
of_is_coproduct (colimit.is_colimit _) initial_is_initial
lemma
category_theory.is_pushout.of_has_binary_coproduct'
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_has_binary_coproduct [has_binary_coproduct X Y] [has_zero_object C] [has_zero_morphisms C] : is_pushout (0 : 0 ⟶ X) (0 : 0 ⟶ Y) coprod.inl coprod.inr
by convert of_is_coproduct (colimit.is_colimit _) has_zero_object.zero_is_initial
lemma
category_theory.is_pushout.of_has_binary_coproduct
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
iso_pushout (h : is_pushout f g inl inr) [has_pushout f g] : P ≅ pushout f g
(colimit.iso_colimit_cocone ⟨_, h.is_colimit⟩).symm
def
category_theory.is_pushout.iso_pushout
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
Any object at the top left of a pullback square is isomorphic to the pullback provided by the `has_limit` API.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inl_iso_pushout_inv (h : is_pushout f g inl inr) [has_pushout f g] : pushout.inl ≫ h.iso_pushout.inv = inl
by { dsimp [iso_pushout, cocone, comm_sq.cocone], simp, }
lemma
category_theory.is_pushout.inl_iso_pushout_inv
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inr_iso_pushout_inv (h : is_pushout f g inl inr) [has_pushout f g] : pushout.inr ≫ h.iso_pushout.inv = inr
by { dsimp [iso_pushout, cocone, comm_sq.cocone], simp, }
lemma
category_theory.is_pushout.inr_iso_pushout_inv
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inl_iso_pushout_hom (h : is_pushout f g inl inr) [has_pushout f g] : inl ≫ h.iso_pushout.hom = pushout.inl
by simp [←iso.eq_comp_inv]
lemma
category_theory.is_pushout.inl_iso_pushout_hom
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inr_iso_pushout_hom (h : is_pushout f g inl inr) [has_pushout f g] : inr ≫ h.iso_pushout.hom = pushout.inr
by simp [←iso.eq_comp_inv]
lemma
category_theory.is_pushout.inr_iso_pushout_hom
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_iso_pushout (h : comm_sq f g inl inr) [has_pushout f g] (i : P ≅ pushout f g) (w₁ : inl ≫ i.hom = pushout.inl) (w₂ : inr ≫ i.hom = pushout.inr) : is_pushout f g inl inr
of_is_colimit' h (limits.is_colimit.of_iso_colimit (colimit.is_colimit _) (@pushout_cocone.ext _ _ _ _ _ _ _ (pushout_cocone.mk _ _ _) _ i w₁ w₂).symm)
lemma
category_theory.is_pushout.of_iso_pushout
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
flip (h : is_pullback fst snd f g) : is_pullback snd fst g f
of_is_limit (@pullback_cone.flip_is_limit _ _ _ _ _ _ _ _ _ _ h.w.symm h.is_limit)
lemma
category_theory.is_pullback.flip
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
flip_iff : is_pullback fst snd f g ↔ is_pullback snd fst g f
⟨flip, flip⟩
lemma
category_theory.is_pullback.flip_iff
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
zero_left (X : C) : is_pullback (0 : 0 ⟶ X) (0 : 0 ⟶ 0) (𝟙 X) (0 : 0 ⟶ X)
{ w := by simp, is_limit' := ⟨{ lift := λ s, 0, fac' := λ s, by simpa using @pullback_cone.equalizer_ext _ _ _ _ _ _ _ s _ 0 (𝟙 _) (by simpa using (pullback_cone.condition s).symm), }⟩ }
lemma
category_theory.is_pullback.zero_left
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[ "lift" ]
The square with `0 : 0 ⟶ 0` on the left and `𝟙 X` on the right is a pullback square.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
zero_top (X : C) : is_pullback (0 : 0 ⟶ 0) (0 : 0 ⟶ X) (0 : 0 ⟶ X) (𝟙 X)
(zero_left X).flip
lemma
category_theory.is_pullback.zero_top
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
The square with `0 : 0 ⟶ 0` on the top and `𝟙 X` on the bottom is a pullback square.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
zero_right (X : C) : is_pullback (0 : X ⟶ 0) (𝟙 X) (0 : 0 ⟶ 0) (0 : X ⟶ 0)
of_iso_pullback (by simp) ((zero_prod_iso X).symm ≪≫ (pullback_zero_zero_iso _ _).symm) (by simp) (by simp)
lemma
category_theory.is_pullback.zero_right
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
The square with `0 : 0 ⟶ 0` on the right and `𝟙 X` on the left is a pullback square.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
zero_bot (X : C) : is_pullback (𝟙 X) (0 : X ⟶ 0) (0 : X ⟶ 0) (0 : 0 ⟶ 0)
(zero_right X).flip
lemma
category_theory.is_pullback.zero_bot
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
The square with `0 : 0 ⟶ 0` on the bottom and `𝟙 X` on the top is a pullback square.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
paste_vert {X₁₁ X₁₂ X₂₁ X₂₂ X₃₁ X₃₂ : C} {h₁₁ : X₁₁ ⟶ X₁₂} {h₂₁ : X₂₁ ⟶ X₂₂} {h₃₁ : X₃₁ ⟶ X₃₂} {v₁₁ : X₁₁ ⟶ X₂₁} {v₁₂ : X₁₂ ⟶ X₂₂} {v₂₁ : X₂₁ ⟶ X₃₁} {v₂₂ : X₂₂ ⟶ X₃₂} (s : is_pullback h₁₁ v₁₁ v₁₂ h₂₁) (t : is_pullback h₂₁ v₂₁ v₂₂ h₃₁) : is_pullback h₁₁ (v₁₁ ≫ v₂₁) (v₁₂ ≫ v₂₂) h₃₁
(of_is_limit (big_square_is_pullback _ _ _ _ _ _ _ s.w t.w t.is_limit s.is_limit))
lemma
category_theory.is_pullback.paste_vert
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
paste_horiz {X₁₁ X₁₂ X₁₃ X₂₁ X₂₂ X₂₃ : C} {h₁₁ : X₁₁ ⟶ X₁₂} {h₁₂ : X₁₂ ⟶ X₁₃} {h₂₁ : X₂₁ ⟶ X₂₂} {h₂₂ : X₂₂ ⟶ X₂₃} {v₁₁ : X₁₁ ⟶ X₂₁} {v₁₂ : X₁₂ ⟶ X₂₂} {v₁₃ : X₁₃ ⟶ X₂₃} (s : is_pullback h₁₁ v₁₁ v₁₂ h₂₁) (t : is_pullback h₁₂ v₁₂ v₁₃ h₂₂) : is_pullback (h₁₁ ≫ h₁₂) v₁₁ v₁₃ (h₂₁ ≫ h₂₂)
(paste_vert s.flip t.flip).flip
lemma
category_theory.is_pullback.paste_horiz
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
Paste two pullback squares "horizontally" to obtain another pullback square.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_bot {X₁₁ X₁₂ X₂₁ X₂₂ X₃₁ X₃₂ : C} {h₁₁ : X₁₁ ⟶ X₁₂} {h₂₁ : X₂₁ ⟶ X₂₂} {h₃₁ : X₃₁ ⟶ X₃₂} {v₁₁ : X₁₁ ⟶ X₂₁} {v₁₂ : X₁₂ ⟶ X₂₂} {v₂₁ : X₂₁ ⟶ X₃₁} {v₂₂ : X₂₂ ⟶ X₃₂} (s : is_pullback h₁₁ (v₁₁ ≫ v₂₁) (v₁₂ ≫ v₂₂) h₃₁) (p : h₁₁ ≫ v₁₂ = v₁₁ ≫ h₂₁) (t : is_pullback h₂₁ v₂₁ v₂₂ h₃₁) : is_pullback h₁₁ v₁₁ v₁₂ h₂₁
of_is_limit (left_square_is_pullback _ _ _ _ _ _ _ p _ t.is_limit s.is_limit)
lemma
category_theory.is_pullback.of_bot
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
Given a pullback square assembled from a commuting square on the top and a pullback square on the bottom, the top square is a pullback square.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_right {X₁₁ X₁₂ X₁₃ X₂₁ X₂₂ X₂₃ : C} {h₁₁ : X₁₁ ⟶ X₁₂} {h₁₂ : X₁₂ ⟶ X₁₃} {h₂₁ : X₂₁ ⟶ X₂₂} {h₂₂ : X₂₂ ⟶ X₂₃} {v₁₁ : X₁₁ ⟶ X₂₁} {v₁₂ : X₁₂ ⟶ X₂₂} {v₁₃ : X₁₃ ⟶ X₂₃} (s : is_pullback (h₁₁ ≫ h₁₂) v₁₁ v₁₃ (h₂₁ ≫ h₂₂)) (p : h₁₁ ≫ v₁₂ = v₁₁ ≫ h₂₁) (t : is_pullback h₁₂ v₁₂ v₁₃ h₂₂) : is_pullback h₁₁ v₁₁ v₁₂ h₂₁
(of_bot s.flip p.symm t.flip).flip
lemma
category_theory.is_pullback.of_right
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
Given a pullback square assembled from a commuting square on the left and a pullback square on the right, the left square is a pullback square.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
paste_vert_iff {X₁₁ X₁₂ X₂₁ X₂₂ X₃₁ X₃₂ : C} {h₁₁ : X₁₁ ⟶ X₁₂} {h₂₁ : X₂₁ ⟶ X₂₂} {h₃₁ : X₃₁ ⟶ X₃₂} {v₁₁ : X₁₁ ⟶ X₂₁} {v₁₂ : X₁₂ ⟶ X₂₂} {v₂₁ : X₂₁ ⟶ X₃₁} {v₂₂ : X₂₂ ⟶ X₃₂} (s : is_pullback h₂₁ v₂₁ v₂₂ h₃₁) (e : h₁₁ ≫ v₁₂ = v₁₁ ≫ h₂₁) : is_pullback h₁₁ (v₁₁ ≫ v₂₁) (v₁₂ ≫ v₂₂) h₃₁ ↔ is_pullback h₁₁ v₁₁ v₁₂ h₂₁
⟨λ h, h.of_bot e s, λ h, h.paste_vert s⟩
lemma
category_theory.is_pullback.paste_vert_iff
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
paste_horiz_iff {X₁₁ X₁₂ X₁₃ X₂₁ X₂₂ X₂₃ : C} {h₁₁ : X₁₁ ⟶ X₁₂} {h₁₂ : X₁₂ ⟶ X₁₃} {h₂₁ : X₂₁ ⟶ X₂₂} {h₂₂ : X₂₂ ⟶ X₂₃} {v₁₁ : X₁₁ ⟶ X₂₁} {v₁₂ : X₁₂ ⟶ X₂₂} {v₁₃ : X₁₃ ⟶ X₂₃} (s : is_pullback h₁₂ v₁₂ v₁₃ h₂₂) (e : h₁₁ ≫ v₁₂ = v₁₁ ≫ h₂₁) : is_pullback (h₁₁ ≫ h₁₂) v₁₁ v₁₃ (h₂₁ ≫ h₂₂) ↔ is_pullback h₁₁ v₁₁ v₁₂ h₂₁
⟨λ h, h.of_right e s, λ h, h.paste_horiz s⟩
lemma
category_theory.is_pullback.paste_horiz_iff
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_is_bilimit {b : binary_bicone X Y} (h : b.is_bilimit) : is_pullback b.fst b.snd (0 : X ⟶ 0) (0 : Y ⟶ 0)
by convert is_pullback.of_is_product' h.is_limit has_zero_object.zero_is_terminal
lemma
category_theory.is_pullback.of_is_bilimit
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_has_biproduct (X Y : C) [has_binary_biproduct X Y] : is_pullback biprod.fst biprod.snd (0 : X ⟶ 0) (0 : Y ⟶ 0)
of_is_bilimit (binary_biproduct.is_bilimit X Y)
lemma
category_theory.is_pullback.of_has_biproduct
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inl_snd' {b : binary_bicone X Y} (h : b.is_bilimit) : is_pullback b.inl (0 : X ⟶ 0) b.snd (0 : 0 ⟶ Y)
by { refine of_right _ (by simp) (of_is_bilimit h), simp, }
lemma
category_theory.is_pullback.inl_snd'
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inl_snd (X Y : C) [has_binary_biproduct X Y] : is_pullback biprod.inl (0 : X ⟶ 0) biprod.snd (0 : 0 ⟶ Y)
inl_snd' (binary_biproduct.is_bilimit X Y)
lemma
category_theory.is_pullback.inl_snd
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
The square ``` X --inl--> X ⊞ Y | | 0 snd | | v v 0 ---0-----> Y ``` is a pullback square.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inr_fst' {b : binary_bicone X Y} (h : b.is_bilimit) : is_pullback b.inr (0 : Y ⟶ 0) b.fst (0 : 0 ⟶ X)
by { apply flip, refine of_bot _ (by simp) (of_is_bilimit h), simp, }
lemma
category_theory.is_pullback.inr_fst'
category_theory.limits.shapes
src/category_theory/limits/shapes/comm_sq.lean
[ "category_theory.comm_sq", "category_theory.limits.opposites", "category_theory.limits.shapes.biproducts", "category_theory.limits.shapes.zero_morphisms", "category_theory.limits.constructions.binary_products", "category_theory.limits.constructions.zero_objects" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83