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

Goal state before:
pp: J : Type u₁
K : Type u₂
inst✝⁴ : SmallCategory J
inst✝³ : Category.{v₂, u₂} K
inst✝² : Small.{v, u₂} K
inst✝¹ : FinCategory J
F : J × K ⥤ Type v
inst✝ : IsFiltered K
x : limit (curry.obj F ⋙ colim)
k : J → K
y : (j : J) → F.obj (j, k j)
e :
  ∀ (j : J),
    (ConcreteCategory.hom (colimit.ι ((curry.obj F).obj j) (k j))) (y j) =
      (ConcreteCategory.hom (limit.π (curry.obj F ⋙ colim) j)) x
k' : K
g : (j : J) → k j ⟶ k'
kf : {j j' : J} → (j ⟶ j') → K
gf hf : {j j' : J} → (f : j ⟶ j') → k' ⟶ kf f
wf :
  ∀ {j j' : J} (f : j ⟶ j'),
    (ConcreteCategory.hom (F.map (𝟙 j' ×ₘ g j' ≫ gf f))) (y j') = (ConcreteCategory.hom (F.map (f ×ₘ g j ≫ hf f))) (y j)
k'' : K
i : {j j' : J} → (f : j ⟶ j') → kf f ⟶ k''
s : ∀ {j₁ j₂ j₃ j₄ : J} (f : j₁ ⟶ j₂) (f' : j₃ ⟶ j₄), gf f ≫ i f = hf f' ≫ i f'
j j' : J
f : j ⟶ j'
⊢ (ConcreteCategory.hom (F.map (𝟙 j' ×ₘ i f))) ((ConcreteCategory.hom (F.map (𝟙 j' ×ₘ g j' ≫ gf f))) (y j')) =
    (ConcreteCategory.hom (F.map (𝟙 j' ×ₘ g j' ≫ gf f ≫ i f))) (y j')

Tactic:
by
            rw [← comp_apply, ← Functor.map_comp, prod_comp, id_comp, assoc]

Goal state after:
Module: Mathlib.CategoryTheory.Adhesive.Basic

Goal state before:
pp: case i'_w
J : Type v'
inst✝⁴ : Category.{u', v'} J
C : Type u
inst✝³ : Category.{v, u} C
W X Y Z✝ : C
f✝ : W ⟶ X
g✝ : W ⟶ Y
h : X ⟶ Z✝
i : Y ⟶ Z✝
inst✝² : Adhesive C
Z A B : C
a : A ⟶ Z
b : B ⟶ Z
inst✝¹ : Mono a
inst✝ : Mono b
K : C
f g : K ⟶ pushout (fst a b) (snd a b)
w : f ≫ pushout.desc a b ⋯ = g ≫ pushout.desc a b ⋯
u : A ⟶ pushout (fst a b) (snd a b) := ⋯
v : B ⟶ pushout (fst a b) (snd a b) := ⋯
this✝¹ : Mono u := ⋯
this✝ : Mono v := ⋯
sq_f_u : IsPullback (fst f u) (snd f u) f u := ⋯
sq_f_v : IsPullback (fst f v) (snd f v) f v := ⋯
sq_g_u : IsPullback (fst g u) (snd g u) g u := ⋯
sq_g_v : IsPullback (fst g v) (snd g v) g v := ⋯
l₁ : pullback f u ⟶ K := ⋯
f₁ : pullback f u ⟶ A := ⋯
l₂ : pullback f v ⟶ K := ⋯
f₂ : pullback f v ⟶ B := ⋯
m₁ : pullback g u ⟶ K := ⋯
g₁ : pullback g u ⟶ A := ⋯
m₂ : pullback g v ⟶ K := ⋯
g₂ : pullback g v ⟶ B := ⋯
w✝² : C
f' : w✝² ⟶ pullback f u
w✝¹ : w✝² ⟶ pullback f v
w✝ : w✝² ⟶ pullback a b
p₁ : IsPullback f' w✝ (snd f u) (fst a b)
left✝ : IsPullback w✝¹ w✝ (snd f v) (snd a b)
h₁ : IsPushout f' w✝¹ (fst f u) (fst f v)
this : Mono f' := ⋯
⊢ fst g v ≫ f = fst g v ≫ g

Tactic:
let sq₂₁ := of_hasPullback m₂ l₁

Goal state after:
case i'_w
J : Type v'
inst✝⁴ : Category.{u', v'} J
C : Type u
inst✝³ : Category.{v, u} C
W X Y Z✝ : C
f✝ : W ⟶ X
g✝ : W ⟶ Y
h : X ⟶ Z✝
i : Y ⟶ Z✝
inst✝² : Adhesive C
Z A B : C
a : A ⟶ Z
b : B ⟶ Z
inst✝¹ : Mono a
inst✝ : Mono b
K : C
f g : K ⟶ pushout (fst a b) (snd a b)
w : f ≫ pushout.desc a b ⋯ = g ≫ pushout.desc a b ⋯
u : A ⟶ pushout (fst a b) (snd a b) := inl (fst a b) (snd a b)
v : B ⟶ pushout (fst a b) (snd a b) := inr (fst a b) (snd a b)
this✝¹ : Mono u := mono_of_isPushout_of_mono_right (of_hasPushout (fst a b) (snd a b))
this✝ : Mono v := mono_of_isPushout_of_mono_left (of_hasPushout (fst a b) (snd a b))
sq_f_u : IsPullback (fst f u) (snd f u) f u := of_hasPullback f u
sq_f_v : IsPullback (fst f v) (snd f v) f v := of_hasPullback f v
sq_g_u : IsPullback (fst g u) (snd g u) g u := of_hasPullback g u
sq_g_v : IsPullback (fst g v) (snd g v) g v := of_hasPullback g v
l₁ : pullback f u ⟶ K := fst f u
f₁ : pullback f u ⟶ A := snd f u
l₂ : pullback f v ⟶ K := fst f v
f₂ : pullback f v ⟶ B := snd f v
m₁ : pullback g u ⟶ K := fst g u
g₁ : pullback g u ⟶ A := snd g u
m₂ : pullback g v ⟶ K := fst g v
g₂ : pullback g v ⟶ B := snd g v
w✝² : C
f' : w✝² ⟶ pullback f u
w✝¹ : w✝² ⟶ pullback f v
w✝ : w✝² ⟶ pullback a b
p₁ : IsPullback f' w✝ (snd f u) (fst a b)
left✝ : IsPullback w✝¹ w✝ (snd f v) (snd a b)
h₁ : IsPushout f' w✝¹ (fst f u) (fst f v)
this : Mono f' := Eq.mpr (id (congrArg (fun _a ↦ Mono _a) (Eq.symm (isoPullback_hom_fst p₁)))) inferInstance
sq₂₁ : IsPullback (fst m₂ l₁) (snd m₂ l₁) m₂ l₁ := of_hasPullback m₂ l₁
⊢ fst g v ≫ f = fst g v ≫ g
Module: Mathlib.CategoryTheory.Limits.VanKampen

Goal state before:
pp: case mpr
C : Type u
inst✝ : Category.{v, u} C
X Y : C
c : BinaryCofan X Y
H :
  ∀ {X' Y' : C} (c' : BinaryCofan X' Y') (αX : X' ⟶ X) (αY : Y' ⟶ Y) (f : c'.pt ⟶ c.pt),
    αX ≫ c.inl = c'.inl ≫ f →
      αY ≫ c.inr = c'.inr ≫ f → (Nonempty (IsColimit c') ↔ IsPullback c'.inl αX f c.inl ∧ IsPullback c'.inr αY f c.inr)
F' : Discrete WalkingPair ⥤ C
c' : Cocone F'
α : F' ⟶ pair X Y
f : c'.pt ⟶ c.pt
hα : α ≫ c.ι = c'.ι ≫ (const (Discrete WalkingPair)).map f
h : NatTrans.Equifibered α
X' : C := F'.obj { as := WalkingPair.left }
Y' : C := F'.obj { as := WalkingPair.right }
this : F' = pair X' Y'
⊢ Nonempty (IsColimit c') ↔ ∀ (j : Discrete WalkingPair), IsPullback (c'.ι.app j) (α.app j) f (c.ι.app j)

Tactic:
clear_value X' Y'

Goal state after:
case mpr
C : Type u
inst✝ : Category.{v, u} C
X Y : C
c : BinaryCofan X Y
H :
  ∀ {X' Y' : C} (c' : BinaryCofan X' Y') (αX : X' ⟶ X) (αY : Y' ⟶ Y) (f : c'.pt ⟶ c.pt),
    αX ≫ c.inl = c'.inl ≫ f →
      αY ≫ c.inr = c'.inr ≫ f → (Nonempty (IsColimit c') ↔ IsPullback c'.inl αX f c.inl ∧ IsPullback c'.inr αY f c.inr)
F' : Discrete WalkingPair ⥤ C
c' : Cocone F'
α : F' ⟶ pair X Y
f : c'.pt ⟶ c.pt
hα : α ≫ c.ι = c'.ι ≫ (const (Discrete WalkingPair)).map f
h : NatTrans.Equifibered α
X' Y' : C
this : F' = pair X' Y'
⊢ Nonempty (IsColimit c') ↔ ∀ (j : Discrete WalkingPair), IsPullback (c'.ι.app j) (α.app j) f (c.ι.app j)
Module: Mathlib.CategoryTheory.Sites.LocallyInjective

Goal state before:
pp: case mp
C : Type u
inst✝³ : Category.{v, u} C
D : Type u'
inst✝² : Category.{v', u'} D
FD : D → D → Type u_1
CD : D → Type w
inst✝¹ : (X Y : D) → FunLike (FD X Y) (CD X) (CD Y)
inst✝ : ConcreteCategory D FD
F : Cᵒᵖ ⥤ D
X : Cᵒᵖ
x y : ToType (F.obj X)
h : equalizerSieve x y = ⊤
⊢ x = y

Tactic:
simpa using (show equalizerSieve x y (𝟙 _) by simp [h])

Goal state after:
Module: Mathlib.CategoryTheory.Sites.LocallyBijective

Goal state before:
pp: case mp
C : Type u
inst✝ : Category.{v, u} C
J : GrothendieckTopology C
F G : Sheaf J (Type w)
f : F ⟶ G
h₁ : ∀ (X : Cᵒᵖ), Function.Injective ⇑(ConcreteCategory.hom (f.hom.app X))
right✝ : IsLocallySurjective f
X : Cᵒᵖ
s : G.obj.obj X
H : Presieve.IsSheafFor F.obj (Presheaf.imageSieve f.hom s).arrows
t : Presieve.FamilyOfElements F.obj (Presheaf.imageSieve f.hom s).arrows :=
  fun Y g hg ↦ Presheaf.localPreimage f.hom s g hg
ht : t.Compatible
Y : C
g : Y ⟶ Opposite.unop X
hg : (Presheaf.imageSieve f.hom s).arrows g
⊢ (ConcreteCategory.hom (G.obj.map g.op)) ((ConcreteCategory.hom (f.hom.app X)) (H.amalgamate t ht)) =
    (ConcreteCategory.hom (G.obj.map g.op)) s

Tactic:
← NatTrans.naturality_apply,

Goal state after:
case mp
C : Type u
inst✝ : Category.{v, u} C
J : GrothendieckTopology C
F G : Sheaf J (Type w)
f : F ⟶ G
h₁ : ∀ (X : Cᵒᵖ), Function.Injective ⇑(ConcreteCategory.hom (f.hom.app X))
right✝ : IsLocallySurjective f
X : Cᵒᵖ
s : G.obj.obj X
H : Presieve.IsSheafFor F.obj (Presheaf.imageSieve f.hom s).arrows
t : Presieve.FamilyOfElements F.obj (Presheaf.imageSieve f.hom s).arrows :=
  fun Y g hg ↦ Presheaf.localPreimage f.hom s g hg
ht : t.Compatible
Y : C
g : Y ⟶ Opposite.unop X
hg : (Presheaf.imageSieve f.hom s).arrows g
⊢ (ConcreteCategory.hom (f.hom.app (Opposite.op Y))) ((ConcreteCategory.hom (F.obj.map g.op)) (H.amalgamate t ht)) =
    (ConcreteCategory.hom (G.obj.map g.op)) s
Module: Mathlib.CategoryTheory.Limits.VanKampen

Goal state before:
pp: case refine_2.uniq
C : Type u
inst✝² : Category.{v, u} C
n : ℕ
f : Fin (n + 1) → C
c₁ : Cofan fun i ↦ f i.succ
c₂ : BinaryCofan (f 0) c₁.pt
t₁ : IsVanKampenColimit c₁
t₂ : IsVanKampenColimit c₂
inst✝¹ : ∀ {Z : C} (i : Z ⟶ c₂.pt), HasPullback c₂.inr i
inst✝ : HasFiniteCoproducts C
j✝ : Fin (n + 1)
F' : Fin (n + 1) → C
c : Cocone (Discrete.functor F')
α : Discrete.functor F' ⟶ Discrete.functor f
i : c.pt ⟶ (extendCofan c₁ c₂).pt
e : α ≫ (extendCofan c₁ c₂).ι = c.ι ≫ (const (Discrete (Fin (n + 1)))).map i
hα : NatTrans.Equifibered α
Hc : IsColimit c
T : C
f₁ : F' 0 ⟶ T
f₂ : (∐ fun j ↦ (Discrete.functor F').obj { as := j.succ }) ⟶ T
f₃ : (BinaryCofan.mk (c.ι.app { as := 0 }) (Sigma.desc fun b ↦ c.ι.app { as := b.succ })).pt ⟶ T
m₁ : c.ι.app { as := 0 } ≫ f₃ = f₁
m₂ : (Sigma.desc fun b ↦ c.ι.app { as := b.succ }) ≫ f₃ = f₂
j : Fin (n + 1)
⊢ c.ι.app { as := j } ≫ f₃ =
    (Cofan.mk T fun i ↦
            Fin.cases f₁ (fun i ↦ Sigma.ι (fun j ↦ (Discrete.functor F').obj { as := j.succ }) i ≫ f₂) i).ι.app
      { as := j }

Tactic:
simp only [Discrete.functor_obj, Cofan.mk_pt, Cofan.mk_ι_app]

Goal state after:
case refine_2.uniq
C : Type u
inst✝² : Category.{v, u} C
n : ℕ
f : Fin (n + 1) → C
c₁ : Cofan fun i ↦ f i.succ
c₂ : BinaryCofan (f 0) c₁.pt
t₁ : IsVanKampenColimit c₁
t₂ : IsVanKampenColimit c₂
inst✝¹ : ∀ {Z : C} (i : Z ⟶ c₂.pt), HasPullback c₂.inr i
inst✝ : HasFiniteCoproducts C
j✝ : Fin (n + 1)
F' : Fin (n + 1) → C
c : Cocone (Discrete.functor F')
α : Discrete.functor F' ⟶ Discrete.functor f
i : c.pt ⟶ (extendCofan c₁ c₂).pt
e : α ≫ (extendCofan c₁ c₂).ι = c.ι ≫ (const (Discrete (Fin (n + 1)))).map i
hα : NatTrans.Equifibered α
Hc : IsColimit c
T : C
f₁ : F' 0 ⟶ T
f₂ : (∐ fun j ↦ (Discrete.functor F').obj { as := j.succ }) ⟶ T
f₃ : (BinaryCofan.mk (c.ι.app { as := 0 }) (Sigma.desc fun b ↦ c.ι.app { as := b.succ })).pt ⟶ T
m₁ : c.ι.app { as := 0 } ≫ f₃ = f₁
m₂ : (Sigma.desc fun b ↦ c.ι.app { as := b.succ }) ≫ f₃ = f₂
j : Fin (n + 1)
⊢ c.ι.app { as := j } ≫ f₃ = Fin.cases f₁ (fun i ↦ Sigma.ι (fun j ↦ F' j.succ) i ≫ f₂) j
Module: Mathlib.CategoryTheory.Sites.Closed

Goal state before:
pp: case refine_2
C : Type u
inst✝ : Category.{v, u} C
J₁ : GrothendieckTopology C
X : C
S : Sieve X
hS : S ∈ J₁ X
⊢ ∀ (x : Presieve.FamilyOfElements (Functor.closedSieves J₁).toFunctor S.arrows), x.Compatible → ∃ t, x.IsAmalgamation t

Tactic:
intro x hx
    rw [Presieve.compatible_iff_sieveCompatible] at hx
    let M := Sieve.bind S fun Y f hf => (x f hf).1
    have : ∀ ⦃Y⦄ (f : Y ⟶ X) (hf : S f), M.pullback f = (x f hf).1 := by
      intro Y f hf
      apply le_antisymm
      · rintro Z u ⟨W, g, f', hf', hg : (x f' hf').1.1 _, c⟩
        rw [Sieve.mem_iff_pullback_eq_top,
          ← show (x (u ≫ f) _).1 = (x f hf).1.pullback u from congr_arg Subtype.val (hx f u hf)]
        conv_lhs => congr; congr; rw [← c] -- Porting note: Originally `simp_rw [← c]`
        rw [show (x (g ≫ f') _).1 = _ from congr_arg Subtype.val (hx f' g hf')]
        apply Sieve.pullback_eq_top_of_mem _ hg
      · apply Sieve.le_pullback_bind S fun Y f hf => (x f hf).1
    refine ⟨⟨_, J₁.close_isClosed M⟩, ?_⟩
    intro Y f hf
    dsimp
    ext1
    dsimp
    rw [← J₁.pullback_close, this _ hf]
    apply le_antisymm (J₁.le_close_of_isClosed le_rfl (x f hf).2) (J₁.le_close _)

Goal state after:
Module: Mathlib.CategoryTheory.Sites.Hypercover.Zero

Goal state before:
pp: C : Type u
inst✝ : Category.{v, u} C
S : C
E : PreZeroHypercover S
c : Cofan E.X
hc : IsColimit c
i : E.I₀
r : PUnit.{w + 1}
⊢ c.inj i ≫ (E.sigmaOfIsColimit hc).f r = E.f i

Tactic:
simp [PreZeroHypercover.sigmaOfIsColimit]

Goal state after:
Module: Mathlib.CategoryTheory.Sites.PrecoverageToGrothendieck

Goal state before:
pp: C : Type u_3
inst✝ : Category.{u_2, u_3} C
J : Precoverage C
P : Cᵒᵖ ⥤ Type u_1
X✝ : C
S✝ : Sieve X✝
X : C
R S : Sieve X
hS : J.Saturate X R
h : ∀ ⦃Y : C⦄ ⦃f : Y ⟶ X⦄, R.arrows f → J.Saturate Y (Sieve.pullback f S)
Y : C
f : Y ⟶ X
H :
  ∀ {X Y : C} {f : Y ⟶ X},
    ∀ R ∈ J.coverings X,
      Presieve.IsSeparatedFor P (Sieve.pullback f (Sieve.generate R)).arrows ∧
        ∀ (x : Presieve.FamilyOfElements P (Sieve.pullback f (Sieve.generate R)).arrows),
          x.Compatible → ∃ t, x.IsAmalgamation t
H1 : ∀ ⦃Y : C⦄ (f : Y ⟶ X), Presieve.IsSeparatedFor P (Sieve.pullback f R).arrows
H1' :
  ∀ ⦃Y : C⦄ (f : Y ⟶ X) (x : Presieve.FamilyOfElements P (Sieve.pullback f R).arrows),
    x.Compatible → ∃ t, x.IsAmalgamation t
H2 :
  ∀ ⦃Y : C⦄ ⦃f : Y ⟶ X⦄,
    R.arrows f → ∀ ⦃Y_1 : C⦄ (f_1 : Y_1 ⟶ Y), Presieve.IsSeparatedFor P (Sieve.pullback f_1 (Sieve.pullback f S)).arrows
H2' :
  ∀ ⦃Y : C⦄ ⦃f : Y ⟶ X⦄,
    R.arrows f →
      ∀ ⦃Y_1 : C⦄ (f_1 : Y_1 ⟶ Y) (x : Presieve.FamilyOfElements P (Sieve.pullback f_1 (Sieve.pullback f S)).arrows),
        x.Compatible → ∃ t, x.IsAmalgamation t
x : Presieve.FamilyOfElements P (Sieve.pullback f S).arrows
hx : x.Compatible
Z : C
g : Z ⟶ Y
ZZ : C
gg : ZZ ⟶ Z
hgg : (Sieve.pullback (𝟙 Z) (Sieve.pullback (g ≫ f) S)).arrows gg
⊢ (Sieve.pullback f S).arrows (gg ≫ g)

Tactic:
by simpa using hgg

Goal state after:
Module: Mathlib.CategoryTheory.Sites.PrecoverageToGrothendieck

Goal state before:
pp: C : Type u_3
inst✝ : Category.{u_2, u_3} C
J : Precoverage C
P : Cᵒᵖ ⥤ Type u_1
X✝ : C
S✝ : Sieve X✝
X : C
R S : Sieve X
hS : J.Saturate X R
h : ∀ ⦃Y : C⦄ ⦃f : Y ⟶ X⦄, R.arrows f → J.Saturate Y (Sieve.pullback f S)
Y : C
f : Y ⟶ X
H :
  ∀ {X Y : C} {f : Y ⟶ X},
    ∀ R ∈ J.coverings X,
      Presieve.IsSeparatedFor P (Sieve.pullback f (Sieve.generate R)).arrows ∧
        ∀ (x : Presieve.FamilyOfElements P (Sieve.pullback f (Sieve.generate R)).arrows),
          x.Compatible → ∃ t, x.IsAmalgamation t
H1 : ∀ ⦃Y : C⦄ (f : Y ⟶ X), Presieve.IsSeparatedFor P (Sieve.pullback f R).arrows
H1' :
  ∀ ⦃Y : C⦄ (f : Y ⟶ X) (x : Presieve.FamilyOfElements P (Sieve.pullback f R).arrows),
    x.Compatible → ∃ t, x.IsAmalgamation t
H2 :
  ∀ ⦃Y : C⦄ ⦃f : Y ⟶ X⦄,
    R.arrows f → ∀ ⦃Y_1 : C⦄ (f_1 : Y_1 ⟶ Y), Presieve.IsSeparatedFor P (Sieve.pullback f_1 (Sieve.pullback f S)).arrows
H2' :
  ∀ ⦃Y : C⦄ ⦃f : Y ⟶ X⦄,
    R.arrows f →
      ∀ ⦃Y_1 : C⦄ (f_1 : Y_1 ⟶ Y) (x : Presieve.FamilyOfElements P (Sieve.pullback f_1 (Sieve.pullback f S)).arrows),
        x.Compatible → ∃ t, x.IsAmalgamation t
x : Presieve.FamilyOfElements P (Sieve.pullback f S).arrows
hx : x.Compatible
y : ⦃Z : C⦄ → (g : Z ⟶ Y) → Presieve.FamilyOfElements P (Sieve.pullback (𝟙 Z) (Sieve.pullback (g ≫ f) S)).arrows :=
  fun Z g ZZ gg hgg ↦ x (gg ≫ g) ⋯
Z : C
g : Z ⟶ Y
⊢ (y g).Compatible

Tactic:
Y₁

Goal state after:
C : Type u_3
inst✝ : Category.{u_2, u_3} C
J : Precoverage C
P : Cᵒᵖ ⥤ Type u_1
X✝ : C
S✝ : Sieve X✝
X : C
R S : Sieve X
hS : J.Saturate X R
h : ∀ ⦃Y : C⦄ ⦃f : Y ⟶ X⦄, R.arrows f → J.Saturate Y (Sieve.pullback f S)
Y : C
f : Y ⟶ X
H :
  ∀ {X Y : C} {f : Y ⟶ X},
    ∀ R ∈ J.coverings X,
      Presieve.IsSeparatedFor P (Sieve.pullback f (Sieve.generate R)).arrows ∧
        ∀ (x : Presieve.FamilyOfElements P (Sieve.pullback f (Sieve.generate R)).arrows),
          x.Compatible → ∃ t, x.IsAmalgamation t
H1 : ∀ ⦃Y : C⦄ (f : Y ⟶ X), Presieve.IsSeparatedFor P (Sieve.pullback f R).arrows
H1' :
  ∀ ⦃Y : C⦄ (f : Y ⟶ X) (x : Presieve.FamilyOfElements P (Sieve.pullback f R).arrows),
    x.Compatible → ∃ t, x.IsAmalgamation t
H2 :
  ∀ ⦃Y : C⦄ ⦃f : Y ⟶ X⦄,
    R.arrows f → ∀ ⦃Y_1 : C⦄ (f_1 : Y_1 ⟶ Y), Presieve.IsSeparatedFor P (Sieve.pullback f_1 (Sieve.pullback f S)).arrows
H2' :
  ∀ ⦃Y : C⦄ ⦃f : Y ⟶ X⦄,
    R.arrows f →
      ∀ ⦃Y_1 : C⦄ (f_1 : Y_1 ⟶ Y) (x : Presieve.FamilyOfElements P (Sieve.pullback f_1 (Sieve.pullback f S)).arrows),
        x.Compatible → ∃ t, x.IsAmalgamation t
x : Presieve.FamilyOfElements P (Sieve.pullback f S).arrows
hx : x.Compatible
y : ⦃Z : C⦄ → (g : Z ⟶ Y) → Presieve.FamilyOfElements P (Sieve.pullback (𝟙 Z) (Sieve.pullback (g ≫ f) S)).arrows :=
  fun Z g ZZ gg hgg ↦ x (gg ≫ g) ⋯
Z : C
g : Z ⟶ Y
Y₁ : C
⊢ ∀ ⦃Y₂ Z_1 : C⦄ (g₁ : Z_1 ⟶ Y₁) (g₂ : Z_1 ⟶ Y₂) ⦃f₁ : Y₁ ⟶ Z⦄ ⦃f₂ : Y₂ ⟶ Z⦄
    (h₁ : (Sieve.pullback (𝟙 Z) (Sieve.pullback (g ≫ f) S)).arrows f₁)
    (h₂ : (Sieve.pullback (𝟙 Z) (Sieve.pullback (g ≫ f) S)).arrows f₂),
    g₁ ≫ f₁ = g₂ ≫ f₂ →
      (ConcreteCategory.hom (P.map g₁.op)) (y g f₁ h₁) = (ConcreteCategory.hom (P.map g₂.op)) (y g f₂ h₂)
Module: Mathlib.CategoryTheory.Sites.Hypercover.Zero

Goal state before:
pp: C : Type u
inst✝ : Category.{v, u} C
J : Precoverage C
S T : C
E : J.ZeroHypercover S
ι : Type (max u v)
Y : ι → C
f : (i : ι) → Y i ⟶ S
h : E.presieve₀ = Presieve.ofArrows Y f
this : ∀ (Z : C) (g : Z ⟶ S), Presieve.ofArrows Y f g → ∃ j, ∃ (h : Z = E.X j), g = eqToHom h ≫ E.f j
⊢ ∃ ι f, (E.restrictIndex f).presieve₀ ∈ J.coverings S

Tactic:
choose j h₁ h₂ using this

Goal state after:
C : Type u
inst✝ : Category.{v, u} C
J : Precoverage C
S T : C
E : J.ZeroHypercover S
ι : Type (max u v)
Y : ι → C
f : (i : ι) → Y i ⟶ S
h : E.presieve₀ = Presieve.ofArrows Y f
j : (Z : C) → (g : Z ⟶ S) → Presieve.ofArrows Y f g → E.I₀
h₁ : ∀ (Z : C) (g : Z ⟶ S) (hg : Presieve.ofArrows Y f g), Z = E.X (j Z g hg)
h₂ : ∀ (Z : C) (g : Z ⟶ S) (hg : Presieve.ofArrows Y f g), g = eqToHom ⋯ ≫ E.f (j Z g hg)
⊢ ∃ ι f, (E.restrictIndex f).presieve₀ ∈ J.coverings S
Module: Mathlib.CategoryTheory.Sites.Continuous

Goal state before:
pp: C : Type u₁
inst✝⁶ : Category.{v₁, u₁} C
D : Type u₂
inst✝⁵ : Category.{v₂, u₂} D
F : C ⥤ D
J : Precoverage C
K : Precoverage D
inst✝⁴ : J.IsStableUnderBaseChange
inst✝³ : J.HasPullbacks
inst✝² : K.IsStableUnderBaseChange
inst✝¹ : K.HasPullbacks
inst✝ : J.PullbacksPreservedBy F
h : J ≤ Precoverage.comap F K
x✝ : Sheaf K.toGrothendieck (Type (max u₁ v₁ u₂ v₂))
G : Dᵒᵖ ⥤ Type (max u₁ v₁ u₂ v₂)
H : Presheaf.IsSheaf K.toGrothendieck G
⊢ Presieve.IsSheaf J.toGrothendieck (F.op ⋙ { obj := G, property := H }.obj)

Tactic:
by
    rw [isSheaf_iff_isSheaf_of_type] at H
    rw [← Precoverage.toGrothendieck_toCoverage, Presieve.isSheaf_coverage] at H ⊢
    intro X R hR
    have : F.PreservesPairwisePullbacks R := J.preservesPairwisePullbacks_of_mem hR
    have : R.HasPairwisePullbacks := J.hasPairwisePullbacks_of_mem hR
    rw [Presieve.IsSheafFor.comp_iff_of_preservesPairwisePullbacks]
    exact H _ (h _ hR)

Goal state after:
Module: Mathlib.CategoryTheory.Sites.CoverPreserving

Goal state before:
pp: C : Type u₁
inst✝² : Category.{v₁, u₁} C
D : Type u₂
inst✝¹ : Category.{v₂, u₂} D
K : GrothendieckTopology D
G : C ⥤ D
inst✝ : RepresentablyFlat G
ℱ : Sheaf K (Type u_1)
Z : C
T : Presieve Z
x : FamilyOfElements (G.op ⋙ ℱ.obj) T
hx : x.Compatible
⊢ ∀ {Y₁ Y₂ : C} {X : D} (f₁ : X ⟶ G.obj Y₁) (f₂ : X ⟶ G.obj Y₂) {g₁ : Y₁ ⟶ Z} {g₂ : Y₂ ⟶ Z} (hg₁ : T g₁) (hg₂ : T g₂),
    f₁ ≫ G.map g₁ = f₂ ≫ G.map g₂ →
      (ConcreteCategory.hom (ℱ.obj.map f₁.op)) (x g₁ hg₁) = (ConcreteCategory.hom (ℱ.obj.map f₂.op)) (x g₂ hg₂)

Tactic:
Y₁

Goal state after:
C : Type u₁
inst✝² : Category.{v₁, u₁} C
D : Type u₂
inst✝¹ : Category.{v₂, u₂} D
K : GrothendieckTopology D
G : C ⥤ D
inst✝ : RepresentablyFlat G
ℱ : Sheaf K (Type u_1)
Z : C
T : Presieve Z
x : FamilyOfElements (G.op ⋙ ℱ.obj) T
hx : x.Compatible
Y₁ : C
⊢ ∀ {Y₂ : C} {X : D} (f₁ : X ⟶ G.obj Y₁) (f₂ : X ⟶ G.obj Y₂) {g₁ : Y₁ ⟶ Z} {g₂ : Y₂ ⟶ Z} (hg₁ : T g₁) (hg₂ : T g₂),
    f₁ ≫ G.map g₁ = f₂ ≫ G.map g₂ →
      (ConcreteCategory.hom (ℱ.obj.map f₁.op)) (x g₁ hg₁) = (ConcreteCategory.hom (ℱ.obj.map f₂.op)) (x g₂ hg₂)
Module: Mathlib.CategoryTheory.Sites.CoverLifting

Goal state before:
pp: C : Type u_1
D : Type u_2
inst✝⁷ : Category.{v_1, u_1} C
inst✝⁶ : Category.{v_2, u_2} D
G : C ⥤ D
A : Type w
inst✝⁵ : Category.{w', w} A
J : GrothendieckTopology C
K : GrothendieckTopology D
inst✝⁴ : G.IsCocontinuous J K
inst✝³ : ∀ (F : Cᵒᵖ ⥤ A), G.op.HasPointwiseRightKanExtension F
inst✝² : G.IsContinuous J K
inst✝¹ : HasWeakSheafify J A
inst✝ : HasWeakSheafify K A
F : Dᵒᵖ ⥤ A
adj₁ : (whiskeringLeft Cᵒᵖ Dᵒᵖ A).obj G.op ⊣ G.op.ran := G.op.ranAdjunction A
adj₂ : presheafToSheaf J A ⊣ sheafToPresheaf J A := sheafificationAdjunction J A
adj₃ : presheafToSheaf K A ⊣ sheafToPresheaf K A := sheafificationAdjunction K A
⊢ toSheafify J (G.op ⋙ F) ≫ ((G.pushforwardContinuousSheafificationCompatibility A J K).hom.app F).hom =
    G.op.whiskerLeft (toSheafify K F)

Tactic:
let adj₄ := G.sheafAdjunctionCocontinuous A J K

Goal state after:
C : Type u_1
D : Type u_2
inst✝⁷ : Category.{v_1, u_1} C
inst✝⁶ : Category.{v_2, u_2} D
G : C ⥤ D
A : Type w
inst✝⁵ : Category.{w', w} A
J : GrothendieckTopology C
K : GrothendieckTopology D
inst✝⁴ : G.IsCocontinuous J K
inst✝³ : ∀ (F : Cᵒᵖ ⥤ A), G.op.HasPointwiseRightKanExtension F
inst✝² : G.IsContinuous J K
inst✝¹ : HasWeakSheafify J A
inst✝ : HasWeakSheafify K A
F : Dᵒᵖ ⥤ A
adj₁ : (whiskeringLeft Cᵒᵖ Dᵒᵖ A).obj G.op ⊣ G.op.ran := G.op.ranAdjunction A
adj₂ : presheafToSheaf J A ⊣ sheafToPresheaf J A := sheafificationAdjunction J A
adj₃ : presheafToSheaf K A ⊣ sheafToPresheaf K A := sheafificationAdjunction K A
adj₄ : G.sheafPushforwardContinuous A J K ⊣ G.sheafPushforwardCocontinuous A J K := G.sheafAdjunctionCocontinuous A J K
⊢ toSheafify J (G.op ⋙ F) ≫ ((G.pushforwardContinuousSheafificationCompatibility A J K).hom.app F).hom =
    G.op.whiskerLeft (toSheafify K F)
Module: Mathlib.CategoryTheory.Sites.DenseSubsite.Basic

Goal state before:
pp: C : Type u_1
inst✝⁴ : Category.{v_1, u_1} C
D : Type u_2
inst✝³ : Category.{v_2, u_2} D
K : GrothendieckTopology D
G : C ⥤ D
inst✝² : G.IsCoverDense K
inst✝¹ : G.IsLocallyFull K
inst✝ : G.IsLocallyFaithful K
ℱ : Sheaf K (Type u_5)
Z : C
T : Presieve Z
x : FamilyOfElements (G.op ⋙ ℱ.obj) T
hx : x.Compatible
⊢ ∀ {Y₁ Y₂ : C} {X : D} (f₁ : X ⟶ G.obj Y₁) (f₂ : X ⟶ G.obj Y₂) {g₁ : Y₁ ⟶ Z} {g₂ : Y₂ ⟶ Z} (hg₁ : T g₁) (hg₂ : T g₂),
    f₁ ≫ G.map g₁ = f₂ ≫ G.map g₂ →
      (ConcreteCategory.hom (ℱ.obj.map f₁.op)) (x g₁ hg₁) = (ConcreteCategory.hom (ℱ.obj.map f₂.op)) (x g₂ hg₂)

Tactic:
Y₁

Goal state after:
C : Type u_1
inst✝⁴ : Category.{v_1, u_1} C
D : Type u_2
inst✝³ : Category.{v_2, u_2} D
K : GrothendieckTopology D
G : C ⥤ D
inst✝² : G.IsCoverDense K
inst✝¹ : G.IsLocallyFull K
inst✝ : G.IsLocallyFaithful K
ℱ : Sheaf K (Type u_5)
Z : C
T : Presieve Z
x : FamilyOfElements (G.op ⋙ ℱ.obj) T
hx : x.Compatible
Y₁ : C
⊢ ∀ {Y₂ : C} {X : D} (f₁ : X ⟶ G.obj Y₁) (f₂ : X ⟶ G.obj Y₂) {g₁ : Y₁ ⟶ Z} {g₂ : Y₂ ⟶ Z} (hg₁ : T g₁) (hg₂ : T g₂),
    f₁ ≫ G.map g₁ = f₂ ≫ G.map g₂ →
      (ConcreteCategory.hom (ℱ.obj.map f₁.op)) (x g₁ hg₁) = (ConcreteCategory.hom (ℱ.obj.map f₂.op)) (x g₂ hg₂)
Module: Mathlib.CategoryTheory.Limits.Constructions.Over.Connected

Goal state before:
pp: J : Type u'
inst✝⁵ : Category.{v', u'} J
C : Type u
inst✝⁴ : Category.{v, u} C
D✝ : Type u_1
inst✝³ : Category.{v_1, u_1} D✝
K : C ⥤ D✝
X : C
B : D✝
inst✝² : IsConnected J
inst✝¹ : HasLimitsOfShape J C
inst✝ : PreservesLimitsOfShape J K
D : J ⥤ CostructuredArrow K B
⊢ PreservesLimit D (CostructuredArrow.toOver K B)

Tactic:
have : PreservesLimit D (CostructuredArrow.toOver K B ⋙ Over.forget B) :=
      inferInstanceAs <| PreservesLimit D (CostructuredArrow.proj K B ⋙ K)

Goal state after:
J : Type u'
inst✝⁵ : Category.{v', u'} J
C : Type u
inst✝⁴ : Category.{v, u} C
D✝ : Type u_1
inst✝³ : Category.{v_1, u_1} D✝
K : C ⥤ D✝
X : C
B : D✝
inst✝² : IsConnected J
inst✝¹ : HasLimitsOfShape J C
inst✝ : PreservesLimitsOfShape J K
D : J ⥤ CostructuredArrow K B
this : PreservesLimit D (CostructuredArrow.toOver K B ⋙ Over.forget B)
⊢ PreservesLimit D (CostructuredArrow.toOver K B)
Module: Mathlib.CategoryTheory.Sites.Over

Goal state before:
pp: case refine_2
C : Type u
inst✝ : Category.{v, u} C
X : C
Y : Over X
R : Presieve Y
⊢ Presieve.functorPushforward (Over.forget X) R ≤ ((overEquiv Y) (generate R)).arrows

Tactic:
rintro Z g ⟨W, u, v, hu, rfl⟩

Goal state after:
case refine_2
C : Type u
inst✝ : Category.{v, u} C
X : C
Y : Over X
R : Presieve Y
Z : C
W : Over X
u : W ⟶ Y
v : Z ⟶ (Over.forget X).obj W
hu : R u
⊢ ((overEquiv Y) (generate R)).arrows (v ≫ (Over.forget X).map u)
Module: Mathlib.CategoryTheory.Simple

Goal state before:
pp: case mp
C : Type u
inst✝² : Category.{v, u} C
inst✝¹ : HasZeroMorphisms C
X Y : C
inst✝ : Simple Y
i : X ≅ Y
Y✝ : C
f : Y✝ ⟶ X
m : Mono f
h : IsIso f
w : f = 0
j : f ≫ i.hom ≠ 0
⊢ False

Tactic:
subst w

Goal state after:
case mp
C : Type u
inst✝² : Category.{v, u} C
inst✝¹ : HasZeroMorphisms C
X Y : C
inst✝ : Simple Y
i : X ≅ Y
Y✝ : C
m : Mono 0
h : IsIso 0
j : 0 ≫ i.hom ≠ 0
⊢ False
Module: Mathlib.CategoryTheory.Simple

Goal state before:
pp: C : Type u
inst✝³ : Category.{v, u} C
inst✝² : HasZeroMorphisms C
X Y : C
inst✝¹ : Simple X
f : X ⟶ Y
inst✝ : HasKernel f
w : f ≠ 0
⊢ kernel.ι f = 0

Tactic:
by_contra h
  have := isIso_of_mono_of_nonzero h
  exact w (eq_zero_of_epi_kernel f)

Goal state after: