mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.CategoryTheory.Limits.Shapes.Diagonal

Goal state before:
pp: C : Type u_1
inst✝² : Category.{v_1, u_1} C
X Y : C
inst✝¹ : HasPullbacks C
U V₁ V₂ : C
f : X ⟶ Y
i : U ⟶ Y
i₁ : V₁ ⟶ pullback f i
i₂ : V₂ ⟶ pullback f i
inst✝ : HasPullback i₁ i₂
⊢ (pullbackDiagonalMapIso f i i₁ i₂).inv ≫
      snd (diagonal f) (map (i₁ ≫ snd f i) (i₂ ≫ snd f i) f f (i₁ ≫ fst f i) (i₂ ≫ fst f i) i ⋯ ⋯) ≫
        fst (i₁ ≫ snd f i) (i₂ ≫ snd f i) =
    fst i₁ i₂

Tactic:
by
  delta pullbackDiagonalMapIso
  simp

Goal state after:
Module: Mathlib.CategoryTheory.MorphismProperty.Limits

Goal state before:
pp: C : Type u
inst✝ : Category.{v, u} C
P : MorphismProperty C
⊢ P.IsStableUnderBaseChange ↔ P.pullbacks ≤ P

Tactic:
constructor

Goal state after:
case mp
C : Type u
inst✝ : Category.{v, u} C
P : MorphismProperty C
⊢ P.IsStableUnderBaseChange → P.pullbacks ≤ P

case mpr
C : Type u
inst✝ : Category.{v, u} C
P : MorphismProperty C
⊢ P.pullbacks ≤ P → P.IsStableUnderBaseChange
Module: Mathlib.CategoryTheory.Limits.Shapes.Diagonal

Goal state before:
pp: C : Type u_1
inst✝² : Category.{v_1, u_1} C
X Y : C
inst✝¹ : HasPullbacks C
U V₁ V₂ : C
f : X ⟶ Y
i : U ⟶ Y
i₁ : V₁ ⟶ pullback f i
i₂ : V₂ ⟶ pullback f i
inst✝ : HasPullback i₁ i₂
⊢ (pullbackDiagonalMapIso f i i₁ i₂).inv ≫
      snd (diagonal f) (map (i₁ ≫ snd f i) (i₂ ≫ snd f i) f f (i₁ ≫ fst f i) (i₂ ≫ fst f i) i ⋯ ⋯) ≫
        snd (i₁ ≫ snd f i) (i₂ ≫ snd f i) =
    snd i₁ i₂

Tactic:
by
  delta pullbackDiagonalMapIso
  simp

Goal state after:
Module: Mathlib.CategoryTheory.MorphismProperty.Limits

Goal state before:
pp: case mpr
C : Type u
inst✝ : Category.{v, u} C
P : MorphismProperty C
h : P.pullbacks ≤ P
⊢ P.IsStableUnderBaseChange

Tactic:
constructor

Goal state after:
case mpr
C : Type u
inst✝ : Category.{v, u} C
P : MorphismProperty C
h : P.pullbacks ≤ P
⊢ ∀ {X Y Y' S : C} {f : X ⟶ S} {g : Y ⟶ S} {f' : Y' ⟶ Y} {g' : Y' ⟶ X}, IsPullback f' g' g f → P g → P g'
Module: Mathlib.CategoryTheory.Limits.Shapes.Diagonal

Goal state before:
pp: C : Type u_1
inst✝² : Category.{v_1, u_1} C
X Y : C
inst✝¹ : HasPullbacks C
U V₁ V₂ : C
f : X ⟶ Y
i : U ⟶ Y
i₁ : V₁ ⟶ pullback f i
i₂ : V₂ ⟶ pullback f i
inst✝ : HasPullback i₁ i₂
⊢ (fst i₁ i₂ ≫ i₁ ≫ fst f i) ≫ diagonal f =
    map i₁ i₂ (i₁ ≫ snd f i) (i₂ ≫ snd f i) (𝟙 V₁) (𝟙 V₂) (snd f i) ⋯ ⋯ ≫
      map (i₁ ≫ snd f i) (i₂ ≫ snd f i) f f (i₁ ≫ fst f i) (i₂ ≫ fst f i) i ⋯ ⋯

Tactic:
ext

Goal state after:
case h₀
C : Type u_1
inst✝² : Category.{v_1, u_1} C
X Y : C
inst✝¹ : HasPullbacks C
U V₁ V₂ : C
f : X ⟶ Y
i : U ⟶ Y
i₁ : V₁ ⟶ pullback f i
i₂ : V₂ ⟶ pullback f i
inst✝ : HasPullback i₁ i₂
⊢ ((fst i₁ i₂ ≫ i₁ ≫ fst f i) ≫ diagonal f) ≫ fst f f =
    (map i₁ i₂ (i₁ ≫ snd f i) (i₂ ≫ snd f i) (𝟙 V₁) (𝟙 V₂) (snd f i) ⋯ ⋯ ≫
        map (i₁ ≫ snd f i) (i₂ ≫ snd f i) f f (i₁ ≫ fst f i) (i₂ ≫ fst f i) i ⋯ ⋯) ≫
      fst f f

case h₁
C : Type u_1
inst✝² : Category.{v_1, u_1} C
X Y : C
inst✝¹ : HasPullbacks C
U V₁ V₂ : C
f : X ⟶ Y
i : U ⟶ Y
i₁ : V₁ ⟶ pullback f i
i₂ : V₂ ⟶ pullback f i
inst✝ : HasPullback i₁ i₂
⊢ ((fst i₁ i₂ ≫ i₁ ≫ fst f i) ≫ diagonal f) ≫ snd f f =
    (map i₁ i₂ (i₁ ≫ snd f i) (i₂ ≫ snd f i) (𝟙 V₁) (𝟙 V₂) (snd f i) ⋯ ⋯ ≫
        map (i₁ ≫ snd f i) (i₂ ≫ snd f i) f f (i₁ ≫ fst f i) (i₂ ≫ fst f i) i ⋯ ⋯) ≫
      snd f f
Module: Mathlib.CategoryTheory.MorphismProperty.Limits

Goal state before:
pp: C : Type u
inst✝⁴ : Category.{v, u} C
P : MorphismProperty C
inst✝³ : P.IsStableUnderBaseChange
inst✝² : P.IsStableUnderComposition
S X X' Y Y' : C
f : X ⟶ S
inst✝¹ : HasPullbacksAlong f
g : Y ⟶ S
f' : X' ⟶ S
g' : Y' ⟶ S
i₁ : X ⟶ X'
inst✝ : HasPullbacksAlong g'
i₂ : Y ⟶ Y'
h₁ : P i₁
h₂ : P i₂
e₁ : f = i₁ ≫ f'
e₂ : g = i₂ ≫ g'
this : HasPullbacksAlong (Over.mk f).hom
⊢ pullback.map f g f' g' i₁ i₂ (𝟙 S) ⋯ ⋯ =
    ((pullbackSymmetry (Over.mk f).hom (Over.mk g).hom).hom ≫
        Over.Hom.left ((Over.pullback (Over.mk f).hom).map (Over.homMk i₂ ⋯))) ≫
      (pullbackSymmetry (Over.mk g').hom (Over.mk f).hom).hom ≫ Over.Hom.left ((Over.pullback g').map (Over.homMk i₁ ⋯))

Tactic:
ext

Goal state after:
case h₀
C : Type u
inst✝⁴ : Category.{v, u} C
P : MorphismProperty C
inst✝³ : P.IsStableUnderBaseChange
inst✝² : P.IsStableUnderComposition
S X X' Y Y' : C
f : X ⟶ S
inst✝¹ : HasPullbacksAlong f
g : Y ⟶ S
f' : X' ⟶ S
g' : Y' ⟶ S
i₁ : X ⟶ X'
inst✝ : HasPullbacksAlong g'
i₂ : Y ⟶ Y'
h₁ : P i₁
h₂ : P i₂
e₁ : f = i₁ ≫ f'
e₂ : g = i₂ ≫ g'
this : HasPullbacksAlong (Over.mk f).hom
⊢ pullback.map f g f' g' i₁ i₂ (𝟙 S) ⋯ ⋯ ≫ pullback.fst f' g' =
    (((pullbackSymmetry (Over.mk f).hom (Over.mk g).hom).hom ≫
          Over.Hom.left ((Over.pullback (Over.mk f).hom).map (Over.homMk i₂ ⋯))) ≫
        (pullbackSymmetry (Over.mk g').hom (Over.mk f).hom).hom ≫
          Over.Hom.left ((Over.pullback g').map (Over.homMk i₁ ⋯))) ≫
      pullback.fst f' g'

case h₁
C : Type u
inst✝⁴ : Category.{v, u} C
P : MorphismProperty C
inst✝³ : P.IsStableUnderBaseChange
inst✝² : P.IsStableUnderComposition
S X X' Y Y' : C
f : X ⟶ S
inst✝¹ : HasPullbacksAlong f
g : Y ⟶ S
f' : X' ⟶ S
g' : Y' ⟶ S
i₁ : X ⟶ X'
inst✝ : HasPullbacksAlong g'
i₂ : Y ⟶ Y'
h₁ : P i₁
h₂ : P i₂
e₁ : f = i₁ ≫ f'
e₂ : g = i₂ ≫ g'
this : HasPullbacksAlong (Over.mk f).hom
⊢ pullback.map f g f' g' i₁ i₂ (𝟙 S) ⋯ ⋯ ≫ pullback.snd f' g' =
    (((pullbackSymmetry (Over.mk f).hom (Over.mk g).hom).hom ≫
          Over.Hom.left ((Over.pullback (Over.mk f).hom).map (Over.homMk i₂ ⋯))) ≫
        (pullbackSymmetry (Over.mk g').hom (Over.mk f).hom).hom ≫
          Over.Hom.left ((Over.pullback g').map (Over.homMk i₁ ⋯))) ≫
      pullback.snd f' g'
Module: Mathlib.RingTheory.RingHomProperties

Goal state before:
pp: P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : StableUnderComposition P
hP' : ∀ {R S : Type u} [inst : CommRing R] [inst_1 : CommRing S] (e : R ≃+* S), P e.toRingHom
⊢ RespectsIso P

Tactic:
constructor

Goal state after:
case left
P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : StableUnderComposition P
hP' : ∀ {R S : Type u} [inst : CommRing R] [inst_1 : CommRing S] (e : R ≃+* S), P e.toRingHom
⊢ ∀ {R S T : Type u} [inst : CommRing R] [inst_1 : CommRing S] [inst_2 : CommRing T] (f : R →+* S) (e : S ≃+* T),
    P f → P (e.toRingHom.comp f)

case right
P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : StableUnderComposition P
hP' : ∀ {R S : Type u} [inst : CommRing R] [inst_1 : CommRing S] (e : R ≃+* S), P e.toRingHom
⊢ ∀ {R S T : Type u} [inst : CommRing R] [inst_1 : CommRing S] [inst_2 : CommRing T] (f : S →+* T) (e : R ≃+* S),
    P f → P (f.comp e.toRingHom)
Module: Mathlib.CategoryTheory.Limits.Shapes.Diagonal

Goal state before:
pp: case refine_1.refine_4
C : Type u_1
inst✝⁵ : Category.{v_1, u_1} C
X Y Z : C
inst✝⁴ : HasPullbacks C
S T : C
f : X ⟶ T
g : Y ⟶ T
i : T ⟶ S
inst✝³ : HasPullback i i
inst✝² : HasPullback f g
inst✝¹ : HasPullback (f ≫ i) (g ≫ i)
inst✝ : HasPullback (diagonal i) (map (f ≫ i) (g ≫ i) i i f g (𝟙 S) ⋯ ⋯)
⊢ map (f ≫ i) (g ≫ i) i i f g (𝟙 S) ⋯ ⋯ ≫ 𝟙 (diagonalObj i) =
    (congrHom ⋯ ⋯).hom ≫
      map ((f ≫ inv (fst i (𝟙 S))) ≫ snd i (𝟙 S)) ((g ≫ inv (fst i (𝟙 S))) ≫ snd i (𝟙 S)) i i
        ((f ≫ inv (fst i (𝟙 S))) ≫ fst i (𝟙 S)) ((g ≫ inv (fst i (𝟙 S))) ≫ fst i (𝟙 S)) (𝟙 S) ⋯ ⋯

Tactic:
ext

Goal state after:
case refine_1.refine_4.h₀
C : Type u_1
inst✝⁵ : Category.{v_1, u_1} C
X Y Z : C
inst✝⁴ : HasPullbacks C
S T : C
f : X ⟶ T
g : Y ⟶ T
i : T ⟶ S
inst✝³ : HasPullback i i
inst✝² : HasPullback f g
inst✝¹ : HasPullback (f ≫ i) (g ≫ i)
inst✝ : HasPullback (diagonal i) (map (f ≫ i) (g ≫ i) i i f g (𝟙 S) ⋯ ⋯)
⊢ (map (f ≫ i) (g ≫ i) i i f g (𝟙 S) ⋯ ⋯ ≫ 𝟙 (diagonalObj i)) ≫ fst i i =
    ((congrHom ⋯ ⋯).hom ≫
        map ((f ≫ inv (fst i (𝟙 S))) ≫ snd i (𝟙 S)) ((g ≫ inv (fst i (𝟙 S))) ≫ snd i (𝟙 S)) i i
          ((f ≫ inv (fst i (𝟙 S))) ≫ fst i (𝟙 S)) ((g ≫ inv (fst i (𝟙 S))) ≫ fst i (𝟙 S)) (𝟙 S) ⋯ ⋯) ≫
      fst i i

case h₁
C : Type u_1
inst✝⁵ : Category.{v_1, u_1} C
X Y Z : C
inst✝⁴ : HasPullbacks C
S T : C
f : X ⟶ T
g : Y ⟶ T
i : T ⟶ S
inst✝³ : HasPullback i i
inst✝² : HasPullback f g
inst✝¹ : HasPullback (f ≫ i) (g ≫ i)
inst✝ : HasPullback (diagonal i) (map (f ≫ i) (g ≫ i) i i f g (𝟙 S) ⋯ ⋯)
⊢ (map (f ≫ i) (g ≫ i) i i f g (𝟙 S) ⋯ ⋯ ≫ 𝟙 (diagonalObj i)) ≫ snd i i =
    ((congrHom ⋯ ⋯).hom ≫
        map ((f ≫ inv (fst i (𝟙 S))) ≫ snd i (𝟙 S)) ((g ≫ inv (fst i (𝟙 S))) ≫ snd i (𝟙 S)) i i
          ((f ≫ inv (fst i (𝟙 S))) ≫ fst i (𝟙 S)) ((g ≫ inv (fst i (𝟙 S))) ≫ fst i (𝟙 S)) (𝟙 S) ⋯ ⋯) ≫
      snd i i
Module: Mathlib.CategoryTheory.MorphismProperty.Limits

Goal state before:
pp: C : Type u
inst✝ : Category.{v, u} C
P : MorphismProperty C
⊢ P.IsStableUnderCobaseChange ↔ P.pushouts ≤ P

Tactic:
constructor

Goal state after:
case mp
C : Type u
inst✝ : Category.{v, u} C
P : MorphismProperty C
⊢ P.IsStableUnderCobaseChange → P.pushouts ≤ P

case mpr
C : Type u
inst✝ : Category.{v, u} C
P : MorphismProperty C
⊢ P.pushouts ≤ P → P.IsStableUnderCobaseChange
Module: Mathlib.CategoryTheory.MorphismProperty.Limits

Goal state before:
pp: case mpr
C : Type u
inst✝ : Category.{v, u} C
P : MorphismProperty C
h : P.pushouts ≤ P
⊢ P.IsStableUnderCobaseChange

Tactic:
constructor

Goal state after:
case mpr
C : Type u
inst✝ : Category.{v, u} C
P : MorphismProperty C
h : P.pushouts ≤ P
⊢ ∀ {A A' B B' : C} {f : A ⟶ A'} {g : A ⟶ B} {f' : B ⟶ B'} {g' : A' ⟶ B'}, IsPushout g f f' g' → P f → P f'
Module: Mathlib.CategoryTheory.MorphismProperty.Limits

Goal state before:
pp: C : Type u
inst✝¹ : Category.{v, u} C
P Q : MorphismProperty C
inst✝ : Q.IsStableUnderCobaseChange
⊢ P.pushouts ≤ Q ↔ P ≤ Q

Tactic:
constructor

Goal state after:
case mp
C : Type u
inst✝¹ : Category.{v, u} C
P Q : MorphismProperty C
inst✝ : Q.IsStableUnderCobaseChange
⊢ P.pushouts ≤ Q → P ≤ Q

case mpr
C : Type u
inst✝¹ : Category.{v, u} C
P Q : MorphismProperty C
inst✝ : Q.IsStableUnderCobaseChange
⊢ P ≤ Q → P.pushouts ≤ Q
Module: Mathlib.CategoryTheory.MorphismProperty.Limits

Goal state before:
pp: C : Type u
inst✝⁴ : Category.{v, u} C
P : MorphismProperty C
inst✝³ : P.IsStableUnderCobaseChange
inst✝² : P.IsStableUnderComposition
S X X' Y Y' : C
f : S ⟶ X
g : S ⟶ Y
f' : S ⟶ X'
g' : S ⟶ Y'
i₁ : X ⟶ X'
inst✝¹ : HasPushoutsAlong f
inst✝ : HasPushoutsAlong g'
i₂ : Y ⟶ Y'
h₁ : P i₁
h₂ : P i₂
e₁ : f' = f ≫ i₁
e₂ : g' = g ≫ i₂
this : HasPushoutsAlong (Under.mk g').hom
⊢ pushout.map f g f' g' i₁ i₂ (𝟙 S) ⋯ ⋯ =
    ((pushoutSymmetry f (Under.mk g).hom).hom ≫ Under.Hom.right ((Under.pushout f).map (Under.homMk i₂ ⋯))) ≫
      (pushoutSymmetry (Under.mk g').hom f).hom ≫ Under.Hom.right ((Under.pushout g').map (Under.homMk i₁ ⋯))

Tactic:
ext

Goal state after:
case h₀
C : Type u
inst✝⁴ : Category.{v, u} C
P : MorphismProperty C
inst✝³ : P.IsStableUnderCobaseChange
inst✝² : P.IsStableUnderComposition
S X X' Y Y' : C
f : S ⟶ X
g : S ⟶ Y
f' : S ⟶ X'
g' : S ⟶ Y'
i₁ : X ⟶ X'
inst✝¹ : HasPushoutsAlong f
inst✝ : HasPushoutsAlong g'
i₂ : Y ⟶ Y'
h₁ : P i₁
h₂ : P i₂
e₁ : f' = f ≫ i₁
e₂ : g' = g ≫ i₂
this : HasPushoutsAlong (Under.mk g').hom
⊢ pushout.inl f g ≫ pushout.map f g f' g' i₁ i₂ (𝟙 S) ⋯ ⋯ =
    pushout.inl f g ≫
      ((pushoutSymmetry f (Under.mk g).hom).hom ≫ Under.Hom.right ((Under.pushout f).map (Under.homMk i₂ ⋯))) ≫
        (pushoutSymmetry (Under.mk g').hom f).hom ≫ Under.Hom.right ((Under.pushout g').map (Under.homMk i₁ ⋯))

case h₁
C : Type u
inst✝⁴ : Category.{v, u} C
P : MorphismProperty C
inst✝³ : P.IsStableUnderCobaseChange
inst✝² : P.IsStableUnderComposition
S X X' Y Y' : C
f : S ⟶ X
g : S ⟶ Y
f' : S ⟶ X'
g' : S ⟶ Y'
i₁ : X ⟶ X'
inst✝¹ : HasPushoutsAlong f
inst✝ : HasPushoutsAlong g'
i₂ : Y ⟶ Y'
h₁ : P i₁
h₂ : P i₂
e₁ : f' = f ≫ i₁
e₂ : g' = g ≫ i₂
this : HasPushoutsAlong (Under.mk g').hom
⊢ pushout.inr f g ≫ pushout.map f g f' g' i₁ i₂ (𝟙 S) ⋯ ⋯ =
    pushout.inr f g ≫
      ((pushoutSymmetry f (Under.mk g).hom).hom ≫ Under.Hom.right ((Under.pushout f).map (Under.homMk i₂ ⋯))) ≫
        (pushoutSymmetry (Under.mk g').hom f).hom ≫ Under.Hom.right ((Under.pushout g').map (Under.homMk i₁ ⋯))
Module: Mathlib.CategoryTheory.Limits.Shapes.Diagonal

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
X Y Z : C
inst✝ : HasPullbacks C
f : X ⟶ Y
g : Y ⟶ Z
⊢ diagonal (f ≫ g) =
    diagonal f ≫ (pullbackDiagonalMapIdIso f f g).inv ≫ snd (diagonal g) (map (f ≫ g) (f ≫ g) g g f f (𝟙 Z) ⋯ ⋯)

Tactic:
ext

Goal state after:
case h₀
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
X Y Z : C
inst✝ : HasPullbacks C
f : X ⟶ Y
g : Y ⟶ Z
⊢ diagonal (f ≫ g) ≫ fst (f ≫ g) (f ≫ g) =
    (diagonal f ≫ (pullbackDiagonalMapIdIso f f g).inv ≫ snd (diagonal g) (map (f ≫ g) (f ≫ g) g g f f (𝟙 Z) ⋯ ⋯)) ≫
      fst (f ≫ g) (f ≫ g)

case h₁
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
X Y Z : C
inst✝ : HasPullbacks C
f : X ⟶ Y
g : Y ⟶ Z
⊢ diagonal (f ≫ g) ≫ snd (f ≫ g) (f ≫ g) =
    (diagonal f ≫ (pullbackDiagonalMapIdIso f f g).inv ≫ snd (diagonal g) (map (f ≫ g) (f ≫ g) g g f f (𝟙 Z) ⋯ ⋯)) ≫
      snd (f ≫ g) (f ≫ g)
Module: Mathlib.CategoryTheory.Limits.Shapes.Diagonal

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
X Y Z : C
inst✝ : HasPullbacks C
f : X ⟶ Y
g : Y ⟶ Z
⊢ f ≫ diagonal g = diagonal (f ≫ g) ≫ map (f ≫ g) (f ≫ g) g g f f (𝟙 Z) ⋯ ⋯

Tactic:
ext

Goal state after:
case h₀
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
X Y Z : C
inst✝ : HasPullbacks C
f : X ⟶ Y
g : Y ⟶ Z
⊢ (f ≫ diagonal g) ≫ fst g g = (diagonal (f ≫ g) ≫ map (f ≫ g) (f ≫ g) g g f f (𝟙 Z) ⋯ ⋯) ≫ fst g g

case h₁
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
X Y Z : C
inst✝ : HasPullbacks C
f : X ⟶ Y
g : Y ⟶ Z
⊢ (f ≫ diagonal g) ≫ snd g g = (diagonal (f ≫ g) ≫ map (f ≫ g) (f ≫ g) g g f f (𝟙 Z) ⋯ ⋯) ≫ snd g g
Module: Mathlib.CategoryTheory.MorphismProperty.Limits

Goal state before:
pp: C : Type u
inst✝¹ : Category.{v, u} C
W : MorphismProperty C
J : Type u_1
inst✝ : Category.{v_1, u_1} J
X₁ X₂ : J ⥤ C
c₁ : Cone X₁
c₂ : Cone X₂
h₁ : IsLimit c₁
h₂ : IsLimit c₂
f : X₁ ⟶ X₂
hf : W.functorCategory J f
φ : c₁.pt ⟶ c₂.pt
hφ : ∀ (j : J), φ ≫ c₂.π.app j = c₁.π.app j ≫ f.app j
⊢ W.limitsOfShape J φ

Tactic:
obtain rfl : φ = h₂.lift (Cone.mk _ (c₁.π ≫ f)) := h₂.hom_ext (fun j ↦ by simp [hφ])

Goal state after:
C : Type u
inst✝¹ : Category.{v, u} C
W : MorphismProperty C
J : Type u_1
inst✝ : Category.{v_1, u_1} J
X₁ X₂ : J ⥤ C
c₁ : Cone X₁
c₂ : Cone X₂
h₁ : IsLimit c₁
h₂ : IsLimit c₂
f : X₁ ⟶ X₂
hf : W.functorCategory J f
hφ : ∀ (j : J), h₂.lift { pt := c₁.pt, π := c₁.π ≫ f } ≫ c₂.π.app j = c₁.π.app j ≫ f.app j
⊢ W.limitsOfShape J (h₂.lift { pt := c₁.pt, π := c₁.π ≫ f })
Module: Mathlib.CategoryTheory.Limits.Shapes.Diagonal

Goal state before:
pp: case w₂
C : Type u_1
inst✝⁵ : Category.{v_1, u_1} C
X Y : C
inst✝⁴ : HasPullbacks C
S T : C
f : X ⟶ T
g : Y ⟶ T
i : T ⟶ S
inst✝³ : HasPullback i i
inst✝² : HasPullback f g
inst✝¹ : HasPullback (f ≫ i) (g ≫ i)
inst✝ : HasPullback (diagonal i) (map (f ≫ i) (g ≫ i) i i f g (𝟙 S) ⋯ ⋯)
⊢ (pullbackDiagonalMapIdIso f g i).symm.hom ≫ snd (diagonal i) (map (f ≫ i) (g ≫ i) i i f g (𝟙 S) ⋯ ⋯) =
    map f g (f ≫ i) (g ≫ i) (𝟙 X) (𝟙 Y) i ⋯ ⋯

Tactic:
ext

Goal state after:
case w₂.h₀
C : Type u_1
inst✝⁵ : Category.{v_1, u_1} C
X Y : C
inst✝⁴ : HasPullbacks C
S T : C
f : X ⟶ T
g : Y ⟶ T
i : T ⟶ S
inst✝³ : HasPullback i i
inst✝² : HasPullback f g
inst✝¹ : HasPullback (f ≫ i) (g ≫ i)
inst✝ : HasPullback (diagonal i) (map (f ≫ i) (g ≫ i) i i f g (𝟙 S) ⋯ ⋯)
⊢ ((pullbackDiagonalMapIdIso f g i).symm.hom ≫ snd (diagonal i) (map (f ≫ i) (g ≫ i) i i f g (𝟙 S) ⋯ ⋯)) ≫
      fst (f ≫ i) (g ≫ i) =
    map f g (f ≫ i) (g ≫ i) (𝟙 X) (𝟙 Y) i ⋯ ⋯ ≫ fst (f ≫ i) (g ≫ i)

case h₁
C : Type u_1
inst✝⁵ : Category.{v_1, u_1} C
X Y : C
inst✝⁴ : HasPullbacks C
S T : C
f : X ⟶ T
g : Y ⟶ T
i : T ⟶ S
inst✝³ : HasPullback i i
inst✝² : HasPullback f g
inst✝¹ : HasPullback (f ≫ i) (g ≫ i)
inst✝ : HasPullback (diagonal i) (map (f ≫ i) (g ≫ i) i i f g (𝟙 S) ⋯ ⋯)
⊢ ((pullbackDiagonalMapIdIso f g i).symm.hom ≫ snd (diagonal i) (map (f ≫ i) (g ≫ i) i i f g (𝟙 S) ⋯ ⋯)) ≫
      snd (f ≫ i) (g ≫ i) =
    map f g (f ≫ i) (g ≫ i) (𝟙 X) (𝟙 Y) i ⋯ ⋯ ≫ snd (f ≫ i) (g ≫ i)
Module: Mathlib.CategoryTheory.Limits.Shapes.Diagonal

Goal state before:
pp: C : Type u_1
inst✝⁵ : Category.{v_1, u_1} C
X Y : C
inst✝⁴ : HasPullbacks C
S T : C
f : X ⟶ T
g : Y ⟶ T
i : T ⟶ S
inst✝³ : HasPullback i i
inst✝² : HasPullback f g
inst✝¹ : HasPullback (f ≫ i) (g ≫ i)
inst✝ : HasPullback (diagonal i) (map (f ≫ i) (g ≫ i) i i f g (𝟙 S) ⋯ ⋯)
⊢ CommSq (fst f g ≫ f) (map f g (f ≫ i) (g ≫ i) (𝟙 X) (𝟙 Y) i ⋯ ⋯) (diagonal i) (map (f ≫ i) (g ≫ i) i i f g (𝟙 S) ⋯ ⋯)

Tactic:
constructor

Goal state after:
C : Type u_1
inst✝⁵ : Category.{v_1, u_1} C
X Y : C
inst✝⁴ : HasPullbacks C
S T : C
f : X ⟶ T
g : Y ⟶ T
i : T ⟶ S
inst✝³ : HasPullback i i
inst✝² : HasPullback f g
inst✝¹ : HasPullback (f ≫ i) (g ≫ i)
inst✝ : HasPullback (diagonal i) (map (f ≫ i) (g ≫ i) i i f g (𝟙 S) ⋯ ⋯)
⊢ autoParam
    ((fst f g ≫ f) ≫ diagonal i = map f g (f ≫ i) (g ≫ i) (𝟙 X) (𝟙 Y) i ⋯ ⋯ ≫ map (f ≫ i) (g ≫ i) i i f g (𝟙 S) ⋯ ⋯)
    CommSq.w._autoParam
Module: Mathlib.CategoryTheory.Limits.Shapes.Diagonal

Goal state before:
pp: C : Type u_1
inst✝⁵ : Category.{v_1, u_1} C
X Y : C
inst✝⁴ : HasPullbacks C
S T : C
f : X ⟶ T
g : Y ⟶ T
i : T ⟶ S
inst✝³ : HasPullback i i
inst✝² : HasPullback f g
inst✝¹ : HasPullback (f ≫ i) (g ≫ i)
inst✝ : HasPullback (diagonal i) (map (f ≫ i) (g ≫ i) i i f g (𝟙 S) ⋯ ⋯)
⊢ autoParam
    ((fst f g ≫ f) ≫ diagonal i = map f g (f ≫ i) (g ≫ i) (𝟙 X) (𝟙 Y) i ⋯ ⋯ ≫ map (f ≫ i) (g ≫ i) i i f g (𝟙 S) ⋯ ⋯)
    CommSq.w._autoParam

Tactic:
ext

Goal state after:
case h₀
C : Type u_1
inst✝⁵ : Category.{v_1, u_1} C
X Y : C
inst✝⁴ : HasPullbacks C
S T : C
f : X ⟶ T
g : Y ⟶ T
i : T ⟶ S
inst✝³ : HasPullback i i
inst✝² : HasPullback f g
inst✝¹ : HasPullback (f ≫ i) (g ≫ i)
inst✝ : HasPullback (diagonal i) (map (f ≫ i) (g ≫ i) i i f g (𝟙 S) ⋯ ⋯)
⊢ ((fst f g ≫ f) ≫ diagonal i) ≫ fst i i =
    (map f g (f ≫ i) (g ≫ i) (𝟙 X) (𝟙 Y) i ⋯ ⋯ ≫ map (f ≫ i) (g ≫ i) i i f g (𝟙 S) ⋯ ⋯) ≫ fst i i

case h₁
C : Type u_1
inst✝⁵ : Category.{v_1, u_1} C
X Y : C
inst✝⁴ : HasPullbacks C
S T : C
f : X ⟶ T
g : Y ⟶ T
i : T ⟶ S
inst✝³ : HasPullback i i
inst✝² : HasPullback f g
inst✝¹ : HasPullback (f ≫ i) (g ≫ i)
inst✝ : HasPullback (diagonal i) (map (f ≫ i) (g ≫ i) i i f g (𝟙 S) ⋯ ⋯)
⊢ ((fst f g ≫ f) ≫ diagonal i) ≫ snd i i =
    (map f g (f ≫ i) (g ≫ i) (𝟙 X) (𝟙 Y) i ⋯ ⋯ ≫ map (f ≫ i) (g ≫ i) i i f g (𝟙 S) ⋯ ⋯) ≫ snd i i
Module: Mathlib.CategoryTheory.Limits.Shapes.Diagonal

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : HasPullbacks C
X Y Z : C
f : X ⟶ Z
g : Y ⟶ Z
⊢ diagonal (fst f g) =
    (pullbackSymmetry f (Over.mk g).hom).hom ≫
      Over.Hom.left ((Over.pullback f).map (Over.homMk (diagonal g) ⋯)) ≫ (diagonalObjPullbackFstIso f g).inv

Tactic:
ext

Goal state after:
case h₀.h₀
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : HasPullbacks C
X Y Z : C
f : X ⟶ Z
g : Y ⟶ Z
⊢ (diagonal (fst f g) ≫ fst (fst f g) (fst f g)) ≫ fst f g =
    (((pullbackSymmetry f (Over.mk g).hom).hom ≫
          Over.Hom.left ((Over.pullback f).map (Over.homMk (diagonal g) ⋯)) ≫ (diagonalObjPullbackFstIso f g).inv) ≫
        fst (fst f g) (fst f g)) ≫
      fst f g

case h₁
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : HasPullbacks C
X Y Z : C
f : X ⟶ Z
g : Y ⟶ Z
⊢ (diagonal (fst f g) ≫ fst (fst f g) (fst f g)) ≫ snd f g =
    (((pullbackSymmetry f (Over.mk g).hom).hom ≫
          Over.Hom.left ((Over.pullback f).map (Over.homMk (diagonal g) ⋯)) ≫ (diagonalObjPullbackFstIso f g).inv) ≫
        fst (fst f g) (fst f g)) ≫
      snd f g

case h₁.h₀
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : HasPullbacks C
X Y Z : C
f : X ⟶ Z
g : Y ⟶ Z
⊢ (diagonal (fst f g) ≫ snd (fst f g) (fst f g)) ≫ fst f g =
    (((pullbackSymmetry f (Over.mk g).hom).hom ≫
          Over.Hom.left ((Over.pullback f).map (Over.homMk (diagonal g) ⋯)) ≫ (diagonalObjPullbackFstIso f g).inv) ≫
        snd (fst f g) (fst f g)) ≫
      fst f g

case h₁
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : HasPullbacks C
X Y Z : C
f : X ⟶ Z
g : Y ⟶ Z
⊢ (diagonal (fst f g) ≫ snd (fst f g) (fst f g)) ≫ snd f g =
    (((pullbackSymmetry f (Over.mk g).hom).hom ≫
          Over.Hom.left ((Over.pullback f).map (Over.homMk (diagonal g) ⋯)) ≫ (diagonalObjPullbackFstIso f g).inv) ≫
        snd (fst f g) (fst f g)) ≫
      snd f g
Module: Mathlib.CategoryTheory.MorphismProperty.Limits

Goal state before:
pp: C : Type u
inst✝¹ : Category.{v, u} C
W : MorphismProperty C
J : Type u_1
inst✝ : Category.{v_1, u_1} J
⊢ W.IsStableUnderLimitsOfShape J ↔ W.limitsOfShape J ≤ W

Tactic:
constructor

Goal state after:
case mp
C : Type u
inst✝¹ : Category.{v, u} C
W : MorphismProperty C
J : Type u_1
inst✝ : Category.{v_1, u_1} J
⊢ W.IsStableUnderLimitsOfShape J → W.limitsOfShape J ≤ W

case mpr
C : Type u
inst✝¹ : Category.{v, u} C
W : MorphismProperty C
J : Type u_1
inst✝ : Category.{v_1, u_1} J
⊢ W.limitsOfShape J ≤ W → W.IsStableUnderLimitsOfShape J
Module: Mathlib.CategoryTheory.MorphismProperty.Limits

Goal state before:
pp: case mpr
C : Type u
inst✝¹ : Category.{v, u} C
W : MorphismProperty C
J : Type u_1
inst✝ : Category.{v_1, u_1} J
h : W.limitsOfShape J ≤ W
⊢ W.IsStableUnderLimitsOfShape J

Tactic:
constructor

Goal state after:
case mpr
C : Type u
inst✝¹ : Category.{v, u} C
W : MorphismProperty C
J : Type u_1
inst✝ : Category.{v_1, u_1} J
h : W.limitsOfShape J ≤ W
⊢ ∀ (X₁ X₂ : J ⥤ C) (c₁ : Cone X₁) (c₂ : Cone X₂) (x : IsLimit c₁) (h₂ : IsLimit c₂) (f : X₁ ⟶ X₂),
    W.functorCategory J f → ∀ (φ : c₁.pt ⟶ c₂.pt), (∀ (j : J), φ ≫ c₂.π.app j = c₁.π.app j ≫ f.app j) → W φ
Module: Mathlib.CategoryTheory.Limits.Shapes.Diagonal

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
X Y : C
inst✝ : HasPullbacks C
S : C
g : Y ⟶ X
f : X ⟶ S
i : pullback (g ≫ f) f ≅ pullback (g ≫ f) (𝟙 X ≫ f) := congrHom ⋯ ⋯
⊢ map (g ≫ f) (𝟙 X ≫ f) f f g (𝟙 X) (𝟙 S) ⋯ ⋯ ≫ 𝟙 (diagonalObj f) = i.inv ≫ map (g ≫ f) f f f g (𝟙 X) (𝟙 S) ⋯ ⋯

Tactic:
ext

Goal state after:
case h₀
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
X Y : C
inst✝ : HasPullbacks C
S : C
g : Y ⟶ X
f : X ⟶ S
i : pullback (g ≫ f) f ≅ pullback (g ≫ f) (𝟙 X ≫ f) := ⋯
⊢ (map (g ≫ f) (𝟙 X ≫ f) f f g (𝟙 X) (𝟙 S) ⋯ ⋯ ≫ 𝟙 (diagonalObj f)) ≫ fst f f =
    (i.inv ≫ map (g ≫ f) f f f g (𝟙 X) (𝟙 S) ⋯ ⋯) ≫ fst f f

case h₁
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
X Y : C
inst✝ : HasPullbacks C
S : C
g : Y ⟶ X
f : X ⟶ S
i : pullback (g ≫ f) f ≅ pullback (g ≫ f) (𝟙 X ≫ f) := ⋯
⊢ (map (g ≫ f) (𝟙 X ≫ f) f f g (𝟙 X) (𝟙 S) ⋯ ⋯ ≫ 𝟙 (diagonalObj f)) ≫ snd f f =
    (i.inv ≫ map (g ≫ f) f f f g (𝟙 X) (𝟙 S) ⋯ ⋯) ≫ snd f f
Module: Mathlib.CategoryTheory.Limits.Shapes.Diagonal

Goal state before:
pp: case w₂
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
X Y : C
inst✝ : HasPullbacks C
S : C
g : Y ⟶ X
f : X ⟶ S
i : pullback (g ≫ f) f ≅ pullback (g ≫ f) (𝟙 X ≫ f) := ⋯
e : pullback (diagonal f) (map (g ≫ f) f f f g (𝟙 X) (𝟙 S) ⋯ ⋯) ≅
  pullback (diagonal f) (map (g ≫ f) (𝟙 X ≫ f) f f g (𝟙 X) (𝟙 S) ⋯ ⋯) := ⋯
⊢ (e ≪≫ pullbackDiagonalMapIdIso g (𝟙 X) f ≪≫ asIso (fst g (𝟙 X))).symm.hom ≫
      snd (diagonal f) (map (g ≫ f) f f f g (𝟙 X) (𝟙 S) ⋯ ⋯) =
    lift (𝟙 Y) g ⋯

Tactic:
ext

Goal state after:
case w₂.h₀
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
X Y : C
inst✝ : HasPullbacks C
S : C
g : Y ⟶ X
f : X ⟶ S
i : pullback (g ≫ f) f ≅ pullback (g ≫ f) (𝟙 X ≫ f) := ⋯
e : pullback (diagonal f) (map (g ≫ f) f f f g (𝟙 X) (𝟙 S) ⋯ ⋯) ≅
  pullback (diagonal f) (map (g ≫ f) (𝟙 X ≫ f) f f g (𝟙 X) (𝟙 S) ⋯ ⋯) := ⋯
⊢ ((e ≪≫ pullbackDiagonalMapIdIso g (𝟙 X) f ≪≫ asIso (fst g (𝟙 X))).symm.hom ≫
        snd (diagonal f) (map (g ≫ f) f f f g (𝟙 X) (𝟙 S) ⋯ ⋯)) ≫
      fst (g ≫ f) f =
    lift (𝟙 Y) g ⋯ ≫ fst (g ≫ f) f

case h₁
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
X Y : C
inst✝ : HasPullbacks C
S : C
g : Y ⟶ X
f : X ⟶ S
i : pullback (g ≫ f) f ≅ pullback (g ≫ f) (𝟙 X ≫ f) := ⋯
e : pullback (diagonal f) (map (g ≫ f) f f f g (𝟙 X) (𝟙 S) ⋯ ⋯) ≅
  pullback (diagonal f) (map (g ≫ f) (𝟙 X ≫ f) f f g (𝟙 X) (𝟙 S) ⋯ ⋯) := ⋯
⊢ ((e ≪≫ pullbackDiagonalMapIdIso g (𝟙 X) f ≪≫ asIso (fst g (𝟙 X))).symm.hom ≫
        snd (diagonal f) (map (g ≫ f) f f f g (𝟙 X) (𝟙 S) ⋯ ⋯)) ≫
      snd (g ≫ f) f =
    lift (𝟙 Y) g ⋯ ≫ snd (g ≫ f) f