mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.AlgebraicGeometry.OpenImmersion

Goal state before:
pp: C : Type u
inst✝ : Category.{v, u} C
R : CommRingCat
f : ↑R
⊢ IsOpenEmbedding
    ⇑(ConcreteCategory.hom
        (LocallyRingedSpace.Hom.toShHom
              (Hom.toLRSHom (Spec.map (CommRingCat.ofHom (algebraMap (↑R) (Localization.Away f)))))).hom.base)

pp: C : Type u
inst✝ : Category.{v, u} C
R : CommRingCat
f : ↑R
hf✝ :
  IsOpenEmbedding
    ⇑(ConcreteCategory.hom
        (LocallyRingedSpace.Hom.toShHom
              (Hom.toLRSHom (Spec.map (CommRingCat.ofHom (algebraMap (↑R) (Localization.Away f)))))).hom.base)
⊢ ∀ (x : ↥(Spec (CommRingCat.of (Localization.Away f)))),
    IsIso
      (PresheafedSpace.Hom.stalkMap
        (LocallyRingedSpace.Hom.toShHom
            (Hom.toLRSHom (Spec.map (CommRingCat.ofHom (algebraMap (↑R) (Localization.Away f)))))).hom
        x)

Tactic:
· exact (PrimeSpectrum.localization_away_isOpenEmbedding (Localization.Away f) f :)

Goal state after:
C : Type u
inst✝ : Category.{v, u} C
R : CommRingCat
f : ↑R
hf✝ :
  IsOpenEmbedding
    ⇑(ConcreteCategory.hom
        (LocallyRingedSpace.Hom.toShHom
              (Hom.toLRSHom (Spec.map (CommRingCat.ofHom (algebraMap (↑R) (Localization.Away f)))))).hom.base)
⊢ ∀ (x : ↥(Spec (CommRingCat.of (Localization.Away f)))),
    IsIso
      (PresheafedSpace.Hom.stalkMap
        (LocallyRingedSpace.Hom.toShHom
            (Hom.toLRSHom (Spec.map (CommRingCat.ofHom (algebraMap (↑R) (Localization.Away f)))))).hom
        x)
Module: Mathlib.Geometry.RingedSpace.OpenImmersion

Goal state before:
pp: C : Type u
inst✝² : Category.{v, u} C
inst✝¹ : HasLimits C
ι : Type v
F : Discrete ι ⥤ SheafedSpace C
inst✝ : HasColimit F
i j : Discrete ι
h : i ≠ j
U : Opens ↑↑(F.obj i).toPresheafedSpace
x : ↑↑((F ⋙ forgetToPresheafedSpace).obj j)
y : ↑↑(F.obj i).toPresheafedSpace
hy : y ∈ ↑U
eq :
  (ConcreteCategory.hom
        (preservesColimitIso (forget C) F ≪≫
            HasColimit.isoOfNatIso Discrete.natIsoFunctor ≪≫
              TopCat.sigmaIsoSigma ((F ⋙ forget C).obj ∘ Discrete.mk)).hom)
      ((ConcreteCategory.hom (colimit.ι F i).hom.base) y) =
    (ConcreteCategory.hom
        (preservesColimitIso (forget C) F ≪≫
            HasColimit.isoOfNatIso Discrete.natIsoFunctor ≪≫
              TopCat.sigmaIsoSigma ((F ⋙ forget C).obj ∘ Discrete.mk)).hom)
      ((ConcreteCategory.hom (preservesColimitIso forgetToPresheafedSpace F).inv.base)
        ((ConcreteCategory.hom (colimit.ι (F ⋙ forgetToPresheafedSpace) j).base) x))
⊢ False

Tactic:
simp_rw [CategoryTheory.Iso.trans_hom, ← TopCat.comp_app, ← PresheafedSpace.comp_base] at eq

Goal state after:
C : Type u
inst✝² : Category.{v, u} C
inst✝¹ : HasLimits C
ι : Type v
F : Discrete ι ⥤ SheafedSpace C
inst✝ : HasColimit F
i j : Discrete ι
h : i ≠ j
U : Opens ↑↑(F.obj i).toPresheafedSpace
x : ↑↑((F ⋙ forgetToPresheafedSpace).obj j)
y : ↑↑(F.obj i).toPresheafedSpace
hy : y ∈ ↑U
eq :
  (ConcreteCategory.hom
        ((preservesColimitIso (forget C) F).hom ≫
          (HasColimit.isoOfNatIso Discrete.natIsoFunctor).hom ≫
            (TopCat.sigmaIsoSigma ((F ⋙ forget C).obj ∘ Discrete.mk)).hom))
      ((ConcreteCategory.hom (colimit.ι F i).hom.base) y) =
    (ConcreteCategory.hom
        ((preservesColimitIso (forget C) F).hom ≫
          (HasColimit.isoOfNatIso Discrete.natIsoFunctor).hom ≫
            (TopCat.sigmaIsoSigma ((F ⋙ forget C).obj ∘ Discrete.mk)).hom))
      ((ConcreteCategory.hom
          (colimit.ι (F ⋙ forgetToPresheafedSpace) j ≫ (preservesColimitIso forgetToPresheafedSpace F).inv).base)
        x)
⊢ False
Module: Mathlib.Geometry.RingedSpace.OpenImmersion

Goal state before:
pp: X Y Z : LocallyRingedSpace
f : X ⟶ Z
g : Y ⟶ Z
H : IsOpenImmersion f
H' : Set.range ⇑(ConcreteCategory.hom g.base) ⊆ Set.range ⇑(ConcreteCategory.hom f.base)
this✝ : IsIso (pullback.snd f g)
this :
  (PreservesPullback.iso (forgetToSheafedSpace ⋙ SheafedSpace.forget CommRingCat) f g).hom ≫
      pullback.fst ((forgetToSheafedSpace ⋙ SheafedSpace.forget CommRingCat).map f)
        ((forgetToSheafedSpace ⋙ SheafedSpace.forget CommRingCat).map g) =
    (pullback.fst f g).base
⊢ Set.range
      ⇑(ConcreteCategory.hom
          (pullback.fst ((forgetToSheafedSpace ⋙ SheafedSpace.forget CommRingCat).map f)
            ((forgetToSheafedSpace ⋙ SheafedSpace.forget CommRingCat).map g))) =
    ⇑(ConcreteCategory.hom f.base) ⁻¹' Set.range ⇑(ConcreteCategory.hom g.base)

Tactic:
rw [TopCat.pullback_fst_range]

Goal state after:
X Y Z : LocallyRingedSpace
f : X ⟶ Z
g : Y ⟶ Z
H : IsOpenImmersion f
H' : Set.range ⇑(ConcreteCategory.hom g.base) ⊆ Set.range ⇑(ConcreteCategory.hom f.base)
this✝ : IsIso (pullback.snd f g)
this :
  (PreservesPullback.iso (forgetToSheafedSpace ⋙ SheafedSpace.forget CommRingCat) f g).hom ≫
      pullback.fst ((forgetToSheafedSpace ⋙ SheafedSpace.forget CommRingCat).map f)
        ((forgetToSheafedSpace ⋙ SheafedSpace.forget CommRingCat).map g) =
    (pullback.fst f g).base
⊢ {x |
      ∃ y,
        (ConcreteCategory.hom ((forgetToSheafedSpace ⋙ SheafedSpace.forget CommRingCat).map f)) x =
          (ConcreteCategory.hom ((forgetToSheafedSpace ⋙ SheafedSpace.forget CommRingCat).map g)) y} =
    ⇑(ConcreteCategory.hom f.base) ⁻¹' Set.range ⇑(ConcreteCategory.hom g.base)
Module: Mathlib.AlgebraicGeometry.Cover.Open

Goal state before:
pp: X Y Z : Scheme
𝒰 : X.OpenCover
f : X ⟶ Z
g : Y ⟶ Z
inst✝ : ∀ (x : 𝒰.I₀), HasPullback (𝒰.f x ≫ f) g
R : CommRingCat
⊢ { I₀ := ↑R, X := fun r ↦ Spec (CommRingCat.of (Localization.Away r)),
        f := fun r ↦ Spec.map (CommRingCat.ofHom (algebraMap (↑R) (Localization.Away r))) }.presieve₀ ∈
    (precoverage IsOpenImmersion).coverings (Spec R)

Tactic:
rw [presieve₀_mem_precoverage_iff]
    refine ⟨fun x ↦ ⟨1, ?_⟩, AlgebraicGeometry.Scheme.isOpenImmersion_SpecMap_localizationAway⟩
    rw [Set.range_eq_univ.mpr ((TopCat.epi_iff_surjective _).mp _)]
    · exact trivial
    · infer_instance

Goal state after:
Module: Mathlib.AlgebraicGeometry.Restrict

Goal state before:
pp: X : Scheme
U : X.Opens
r : ↑Γ(↑U, ⊤)
⊢ U.ι ''ᵁ (↑U).basicOpen r = X.basicOpen ((ConcreteCategory.hom (X.presheaf.map (eqToHom ⋯).op)) r)

Tactic:
refine (Scheme.image_basicOpen (X.ofRestrict U.isOpenEmbedding) r).trans ?_
  rw [← Scheme.basicOpen_res_eq _ _ (eqToHom U.isOpenEmbedding_obj_top).op]
  rw [← CommRingCat.comp_apply, ← CategoryTheory.Functor.map_comp, ← op_comp, eqToHom_trans,
    eqToHom_refl, op_id]
  congr
  exact (PresheafedSpace.IsOpenImmersion.ofRestrict_invApp _ _ _).trans
    (CategoryTheory.Functor.map_id _ _).symm

Goal state after:
Module: Mathlib.AlgebraicGeometry.StructureSheaf

Goal state before:
pp: R M : Type u
inst✝² : CommRing R
inst✝¹ : AddCommGroup M
inst✝ : Module R M
f : R
a : M
b : ↥(Submonoid.powers f)
c : M
d : ↥(Submonoid.powers f)
h_eq : (toBasicOpenₗ R M f) (LocalizedModule.mk a b) = (toBasicOpenₗ R M f) (LocalizedModule.mk c d)
this : f ∈ (⊥.colon {d • a - b • c}).radical
⊢ ∃ u, u • d • a = u • b • c

Tactic:
obtain ⟨n, hn⟩ := this

Goal state after:
R M : Type u
inst✝² : CommRing R
inst✝¹ : AddCommGroup M
inst✝ : Module R M
f : R
a : M
b : ↥(Submonoid.powers f)
c : M
d : ↥(Submonoid.powers f)
h_eq : (toBasicOpenₗ R M f) (LocalizedModule.mk a b) = (toBasicOpenₗ R M f) (LocalizedModule.mk c d)
n : ℕ
hn : f ^ n ∈ ⊥.colon {d • a - b • c}
⊢ ∃ u, u • d • a = u • b • c
Module: Mathlib.AlgebraicGeometry.Restrict

Goal state before:
pp: X : Scheme
U : X.Opens
⊢ X.isoOfEq ⋯ = Iso.refl ↑U

Tactic:
by
  ext1
  rw [← cancel_mono U.ι, Scheme.isoOfEq_hom_ι, Iso.refl_hom, Category.id_comp]

Goal state after:
Module: Mathlib.AlgebraicGeometry.AffineScheme

Goal state before:
pp: X Y : Scheme
f : X ⟶ Y
V : X.Opens
U : Y.Opens
hU : IsAffineOpen U
hV : IsAffineOpen V
i : V ≤ f ⁻¹ᵁ U
this : IsAffine ↑U
⊢ Spec.map (Scheme.Hom.appLE f U V i) ≫ Spec.map (Y.presheaf.map (eqToHom ⋯).op) ≫ (↑U).isoSpec.inv ≫ U.ι =
    Spec.map (X.presheaf.map (eqToHom ⋯).op) ≫ (↑V).isoSpec.inv ≫ X.homOfLE i ≫ f ∣_ U ≫ U.ι

Tactic:
← Category.assoc _ (f ∣_ U) U.ι,

Goal state after:
X Y : Scheme
f : X ⟶ Y
V : X.Opens
U : Y.Opens
hU : IsAffineOpen U
hV : IsAffineOpen V
i : V ≤ f ⁻¹ᵁ U
this : IsAffine ↑U
⊢ Spec.map (Scheme.Hom.appLE f U V i) ≫ Spec.map (Y.presheaf.map (eqToHom ⋯).op) ≫ (↑U).isoSpec.inv ≫ U.ι =
    Spec.map (X.presheaf.map (eqToHom ⋯).op) ≫ (↑V).isoSpec.inv ≫ (X.homOfLE i ≫ f ∣_ U) ≫ U.ι
Module: Mathlib.AlgebraicGeometry.AffineScheme

Goal state before:
pp: X Y : Scheme
f : X ⟶ Y
U : Y.Opens
hU : IsAffineOpen U
h : IsAffineOpen (f ⁻¹ᵁ U)
r : ↑Γ(Y, U)
this✝ : IsLocalization.Away r ↑Γ(Y, Y.basicOpen r)
this :
  IsLocalization.Away ((ConcreteCategory.hom (Scheme.Hom.app f U)) r)
    ↑Γ(X, X.basicOpen ((ConcreteCategory.hom (Scheme.Hom.app f U)) r))
⊢ (CommRingCat.Hom.hom (Scheme.Hom.app f (Y.basicOpen r))).comp (algebraMap ↑Γ(Y, U) ↑Γ(Y, Y.basicOpen r)) =
    (CommRingCat.Hom.hom
          (CommRingCat.ofHom
              (IsLocalization.map (↑Γ(X, X.basicOpen ((ConcreteCategory.hom (Scheme.Hom.app f U)) r)))
                (CommRingCat.Hom.hom (Scheme.Hom.app f U)) ⋯) ≫
            X.presheaf.map (eqToHom ⋯).op)).comp
      (algebraMap ↑Γ(Y, U) ↑Γ(Y, Y.basicOpen r))

Tactic:
CommRingCat.hom_comp,

Goal state after:
X Y : Scheme
f : X ⟶ Y
U : Y.Opens
hU : IsAffineOpen U
h : IsAffineOpen (f ⁻¹ᵁ U)
r : ↑Γ(Y, U)
this✝ : IsLocalization.Away r ↑Γ(Y, Y.basicOpen r)
this :
  IsLocalization.Away ((ConcreteCategory.hom (Scheme.Hom.app f U)) r)
    ↑Γ(X, X.basicOpen ((ConcreteCategory.hom (Scheme.Hom.app f U)) r))
⊢ (CommRingCat.Hom.hom (Scheme.Hom.app f (Y.basicOpen r))).comp (algebraMap ↑Γ(Y, U) ↑Γ(Y, Y.basicOpen r)) =
    ((CommRingCat.Hom.hom (X.presheaf.map (eqToHom ⋯).op)).comp
          (CommRingCat.Hom.hom
            (CommRingCat.ofHom
              (IsLocalization.map (↑Γ(X, X.basicOpen ((ConcreteCategory.hom (Scheme.Hom.app f U)) r)))
                (CommRingCat.Hom.hom (Scheme.Hom.app f U)) ⋯)))).comp
      (algebraMap ↑Γ(Y, U) ↑Γ(Y, Y.basicOpen r))
Module: Mathlib.AlgebraicGeometry.GammaSpecAdjunction

Goal state before:
pp: R : CommRingCat
⊢ Spec.map ((Scheme.ΓSpecIso R).hom ≫ (Scheme.ΓSpecIso R).inv) = 𝟙 (Spec Γ(Spec R, ⊤))

Tactic:
Iso.hom_inv_id,

Goal state after:
R : CommRingCat
⊢ Spec.map (𝟙 Γ(Spec R, ⊤)) = 𝟙 (Spec Γ(Spec R, ⊤))
Module: Mathlib.AlgebraicGeometry.AffineScheme

Goal state before:
pp: X : Scheme
U : X.Opens
hU : IsAffineOpen U
x : ↥U
hx : IsClosed {↑x}
hx₀ : IsClosed {x}
⊢ IsClosed {hU.isoSpec.hom x}

Tactic:
← Set.image_singleton

Goal state after:
X : Scheme
U : X.Opens
hU : IsAffineOpen U
x : ↥U
hx : IsClosed {↑x}
hx₀ : IsClosed {x}
⊢ IsClosed (⇑hU.isoSpec.hom '' {x})
Module: Mathlib.CategoryTheory.Monoidal.Cartesian.Over

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : HasPullbacks C
X A B Y : C
f : X ⟶ Y
gA : A ⟶ Y
gB : B ⟶ Y
⊢ Hom.left (prodComparisonIso (pullback f) (mk gA) (mk gB)).inv ≫
      pullback.fst (pullback.fst gA gB ≫ gA) f ≫ pullback.snd gA gB =
    pullback.snd ((pullback f).obj (mk gA)).hom ((pullback f).obj (mk gB)).hom ≫ pullback.fst (mk gB).hom f

Tactic:
rw [← cancel_epi (prodComparisonIso (Over.pullback f) _ _).hom.left,
    Over.hom_left_inv_left_assoc]

Goal state after:
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : HasPullbacks C
X A B Y : C
f : X ⟶ Y
gA : A ⟶ Y
gB : B ⟶ Y
⊢ pullback.fst (pullback.fst gA gB ≫ gA) f ≫ pullback.snd gA gB =
    Hom.left (prodComparisonIso (pullback f) (mk gA) (mk gB)).hom ≫
      pullback.snd ((pullback f).obj (mk gA)).hom ((pullback f).obj (mk gB)).hom ≫ pullback.fst (mk gB).hom f
Module: Mathlib.CategoryTheory.Monoidal.Cartesian.Over

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : HasPullbacks C
X A B Y : C
f : X ⟶ Y
gA : A ⟶ Y
gB : B ⟶ Y
⊢ Hom.left (prodComparisonIso (pullback f) (mk gA) (mk gB)).inv ≫ pullback.snd (pullback.fst gA gB ≫ gA) f =
    pullback.snd ((pullback f).obj (mk gA)).hom ((pullback f).obj (mk gB)).hom ≫ pullback.snd (mk gB).hom f

Tactic:
rw [← cancel_epi (prodComparisonIso (Over.pullback f) _ _).hom.left,
    Over.hom_left_inv_left_assoc]

Goal state after:
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : HasPullbacks C
X A B Y : C
f : X ⟶ Y
gA : A ⟶ Y
gB : B ⟶ Y
⊢ pullback.snd (pullback.fst gA gB ≫ gA) f =
    Hom.left (prodComparisonIso (pullback f) (mk gA) (mk gB)).hom ≫
      pullback.snd ((pullback f).obj (mk gA)).hom ((pullback f).obj (mk gB)).hom ≫ pullback.snd (mk gB).hom f
Module: Mathlib.Geometry.RingedSpace.PresheafedSpace.Gluing

Goal state before:
pp: C : Type u
inst✝ : Category.{v, u} C
D : GlueData C
i j k : D.J
S : Set ↑↑(D.V (i, j))
eq₁ :
  (PreservesPullback.iso (forget C) (D.f i j) (D.f i k)).hom ≫
      pullback.fst ((forget C).map (D.f i j)) ((forget C).map (D.f i k)) =
    (pullback.fst (D.f i j) (D.f i k)).base
⊢ ⇑(ConcreteCategory.hom (pullback.snd (D.f i j) (D.f i k)).base) ''
      ⇑(ConcreteCategory.hom (pullback.fst (D.f i j) (D.f i k)).base) ⁻¹' S =
    ⇑(ConcreteCategory.hom (D.f i k).base) ⁻¹' ⇑(ConcreteCategory.hom (D.f i j).base) '' S

Tactic:
have eq₂ : _ = (π₂ i, j, k).base := PreservesPullback.iso_hom_snd (forget C) _ _

Goal state after:
C : Type u
inst✝ : Category.{v, u} C
D : GlueData C
i j k : D.J
S : Set ↑↑(D.V (i, j))
eq₁ :
  (PreservesPullback.iso (forget C) (D.f i j) (D.f i k)).hom ≫
      pullback.fst ((forget C).map (D.f i j)) ((forget C).map (D.f i k)) =
    (pullback.fst (D.f i j) (D.f i k)).base
eq₂ :
  (PreservesPullback.iso (forget C) (D.f i j) (D.f i k)).hom ≫
      pullback.snd ((forget C).map (D.f i j)) ((forget C).map (D.f i k)) =
    (pullback.snd (D.f i j) (D.f i k)).base
⊢ ⇑(ConcreteCategory.hom (pullback.snd (D.f i j) (D.f i k)).base) ''
      ⇑(ConcreteCategory.hom (pullback.fst (D.f i j) (D.f i k)).base) ⁻¹' S =
    ⇑(ConcreteCategory.hom (D.f i k).base) ⁻¹' ⇑(ConcreteCategory.hom (D.f i j).base) '' S
Module: Mathlib.AlgebraicGeometry.Gluing

Goal state before:
pp: D : GlueData
⊢ D.glued.toSheafedSpace ≅ D.toLocallyRingedSpaceGlueData.toSheafedSpaceGlueData.glued

Tactic:
refine LocallyRingedSpace.forgetToSheafedSpace.mapIso ?_ ≪≫
    LocallyRingedSpace.GlueData.isoSheafedSpace _

Goal state after:
D : GlueData
⊢ D.glued.toLocallyRingedSpace ≅ D.toLocallyRingedSpaceGlueData.glued
Module: Mathlib.AlgebraicGeometry.Gluing

Goal state before:
pp: D : GlueData
i : D.J
⊢ (((D.mapGlueData forgetToLocallyRingedSpace).mapGlueData LocallyRingedSpace.forgetToSheafedSpace).ι i).hom.base ≫
      D.toLocallyRingedSpaceGlueData.isoSheafedSpace.inv.hom.base ≫
        (LocallyRingedSpace.forgetToSheafedSpace.map D.isoLocallyRingedSpace.inv).hom.base =
    (D.ι i).base

Tactic:
rw [← Category.assoc, ← PresheafedSpace.comp_base,
    ← InducedCategory.comp_hom, D.toLocallyRingedSpaceGlueData.ι_isoSheafedSpace_inv i,
    ← PresheafedSpace.comp_base]

Goal state after:
D : GlueData
i : D.J
⊢ ((LocallyRingedSpace.Hom.toShHom (D.toLocallyRingedSpaceGlueData.ι i)).hom ≫
        (LocallyRingedSpace.forgetToSheafedSpace.map D.isoLocallyRingedSpace.inv).hom).base =
    (D.ι i).base
Module: Mathlib.AlgebraicGeometry.Gluing

Goal state before:
pp: X : Scheme
𝒰 : X.OpenCover
x : ↥X
⊢ ∃ a, (fromGlued 𝒰) a = x

Tactic:
obtain ⟨y, h⟩ := 𝒰.covers x

Goal state after:
X : Scheme
𝒰 : X.OpenCover
x : ↥X
y : ↥(𝒰.X (idx 𝒰 x))
h : (𝒰.f (idx 𝒰 x)) y = x
⊢ ∃ a, (fromGlued 𝒰) a = x
Module: Mathlib.AlgebraicGeometry.Limits

Goal state before:
pp: ι : Type u
f : ι → Scheme
σ : Type v
g : σ → Scheme
X Y : Scheme
⊢ IsOpenImmersion coprod.inl

Tactic:
by
  rw [← ι_left_coprodIsoSigma_inv]; infer_instance

Goal state after:
Module: Mathlib.AlgebraicGeometry.Limits

Goal state before:
pp: case refine_1
ι : Type u
f✝ : ι → Scheme
σ : Type v
g : σ → Scheme
X✝ Y✝ : Scheme
X Y : Scheme
c : BinaryCofan X Y
hc : IsColimit c
X' Y' : Scheme
αX : X' ⟶ X
αY : Y' ⟶ Y
f : (BinaryCofan.mk coprod.inl coprod.inr).pt ⟶ (BinaryCofan.mk coprod.inl coprod.inr).pt
h₁ : αX ≫ coprod.inl = coprod.inl ≫ f
h₂ : αY ≫ coprod.inr = coprod.inr ≫ f
h₁' :
  ∀ (x : ↥X'),
    (TopCat.Hom.hom f.base) ((TopCat.Hom.hom coprod.inl.base) x) =
      (TopCat.Hom.hom coprod.inl.base) ((TopCat.Hom.hom αX.base) x)
h₂' :
  ∀ (x : ↥Y'),
    (TopCat.Hom.hom f.base) ((TopCat.Hom.hom coprod.inr.base) x) =
      (TopCat.Hom.hom coprod.inr.base) ((TopCat.Hom.hom αY.base) x)
⊢ IsPullback (BinaryCofan.mk coprod.inl coprod.inr).inl αX f (BinaryCofan.mk coprod.inl coprod.inr).inl ∧
    IsPullback (BinaryCofan.mk coprod.inl coprod.inr).inr αY f (BinaryCofan.mk coprod.inl coprod.inr).inr

Tactic:
refine ⟨(IsOpenImmersion.isPullback _ _ _ _ h₁.symm ?_).flip,
        (IsOpenImmersion.isPullback _ _ _ _ h₂.symm ?_).flip⟩

Goal state after:
case refine_1.refine_1
ι : Type u
f✝ : ι → Scheme
σ : Type v
g : σ → Scheme
X✝ Y✝ : Scheme
X Y : Scheme
c : BinaryCofan X Y
hc : IsColimit c
X' Y' : Scheme
αX : X' ⟶ X
αY : Y' ⟶ Y
f : (BinaryCofan.mk coprod.inl coprod.inr).pt ⟶ (BinaryCofan.mk coprod.inl coprod.inr).pt
h₁ : αX ≫ coprod.inl = coprod.inl ≫ f
h₂ : αY ≫ coprod.inr = coprod.inr ≫ f
h₁' :
  ∀ (x : ↥X'),
    (TopCat.Hom.hom f.base) ((TopCat.Hom.hom coprod.inl.base) x) =
      (TopCat.Hom.hom coprod.inl.base) ((TopCat.Hom.hom αX.base) x)
h₂' :
  ∀ (x : ↥Y'),
    (TopCat.Hom.hom f.base) ((TopCat.Hom.hom coprod.inr.base) x) =
      (TopCat.Hom.hom coprod.inr.base) ((TopCat.Hom.hom αY.base) x)
⊢ f ⁻¹ᵁ Scheme.Hom.opensRange coprod.inl = Scheme.Hom.opensRange coprod.inl

case refine_1.refine_2
ι : Type u
f✝ : ι → Scheme
σ : Type v
g : σ → Scheme
X✝ Y✝ : Scheme
X Y : Scheme
c : BinaryCofan X Y
hc : IsColimit c
X' Y' : Scheme
αX : X' ⟶ X
αY : Y' ⟶ Y
f : (BinaryCofan.mk coprod.inl coprod.inr).pt ⟶ (BinaryCofan.mk coprod.inl coprod.inr).pt
h₁ : αX ≫ coprod.inl = coprod.inl ≫ f
h₂ : αY ≫ coprod.inr = coprod.inr ≫ f
h₁' :
  ∀ (x : ↥X'),
    (TopCat.Hom.hom f.base) ((TopCat.Hom.hom coprod.inl.base) x) =
      (TopCat.Hom.hom coprod.inl.base) ((TopCat.Hom.hom αX.base) x)
h₂' :
  ∀ (x : ↥Y'),
    (TopCat.Hom.hom f.base) ((TopCat.Hom.hom coprod.inr.base) x) =
      (TopCat.Hom.hom coprod.inr.base) ((TopCat.Hom.hom αY.base) x)
⊢ f ⁻¹ᵁ Scheme.Hom.opensRange coprod.inr = Scheme.Hom.opensRange coprod.inr
Module: Mathlib.AlgebraicGeometry.Limits

Goal state before:
pp: U X Y : Scheme
f : U ⟶ X
g : U ⟶ Y
inst✝¹ : IsOpenImmersion f
inst✝ : IsOpenImmersion g
i j : WalkingSpan
t : i ⟶ j
⊢ IsOpenImmersion ((span f g).map t)

Tactic:
by
  obtain (a | (a | a)) := t
  · simp only [WidePushoutShape.hom_id, CategoryTheory.Functor.map_id]
    infer_instance
  · simpa
  · simpa

Goal state after:
Module: Mathlib.AlgebraicGeometry.Morphisms.Basic

Goal state before:
pp: P : MorphismProperty Scheme
inst✝² : IsZariskiLocalAtSource P
X Y : Scheme
f : X ⟶ Y
inst✝¹ : IsZariskiLocalAtTarget P
inst✝ : P.RespectsRight IsOpenImmersion
hf : ∀ (x : ↥X), ∃ U V, ∃ (_ : x ∈ V.carrier) (e : V ≤ f ⁻¹ᵁ U), P (Scheme.Hom.resLE f U V e)
⊢ P f

Tactic:
choose U V hxU e hf using hf

Goal state after:
P : MorphismProperty Scheme
inst✝² : IsZariskiLocalAtSource P
X Y : Scheme
f : X ⟶ Y
inst✝¹ : IsZariskiLocalAtTarget P
inst✝ : P.RespectsRight IsOpenImmersion
U : ↥X → Y.Opens
V : ↥X → X.Opens
hxU : ∀ (x : ↥X), x ∈ (V x).carrier
e : ∀ (x : ↥X), V x ≤ f ⁻¹ᵁ U x
hf : ∀ (x : ↥X), P (Scheme.Hom.resLE f (U x) (V x) ⋯)
⊢ P f
Module: Mathlib.AlgebraicGeometry.Pullbacks

Goal state before:
pp: case refine_2.h₀
X Y Z : Scheme
𝒰✝ : X.OpenCover
f✝ : X ⟶ Z
g : Y ⟶ Z
inst✝ : ∀ (i : 𝒰✝.I₀), HasPullback (𝒰✝.f i ≫ f✝) g
s : PullbackCone f✝ g
f : X ⟶ Y
𝒰 : Y.OpenCover
𝒱 : (i : (Precoverage.ZeroHypercover.pullback₁ f 𝒰).I₀) → ((Precoverage.ZeroHypercover.pullback₁ f 𝒰).X i).OpenCover
i : (openCoverOfBase 𝒰 f f).I₀
j : (𝒱 i).I₀
H :
  pullback.snd (pullback.diagonal f) ((diagonalCover f 𝒰 𝒱).f ⟨i, (j, j)⟩) ≫
      pullback.snd ((𝒱 i).f j ≫ pullback.snd f (𝒰.f i)) ((𝒱 i).f j ≫ pullback.snd f (𝒰.f i)) =
    pullback.snd (pullback.diagonal f) ((diagonalCover f 𝒰 𝒱).f ⟨i, (j, j)⟩) ≫
      pullback.fst ((𝒱 i).f j ≫ pullback.snd f (𝒰.f i)) ((𝒱 i).f j ≫ pullback.snd f (𝒰.f i))
⊢ pullback.map (pullback.diagonal f) ((diagonalCover f 𝒰 𝒱).f ⟨i, (j, j)⟩) (pullback.diagonal f)
        (pullback.map ((𝒱 i).f j ≫ pullback.snd f (𝒰.f i)) ((𝒱 i).f j ≫ pullback.snd f (𝒰.f i)) f f
          ((𝒱 i).f j ≫ pullback.fst f (𝒰.f i)) ((𝒱 i).f j ≫ pullback.fst f (𝒰.f i)) (𝒰.f i) ⋯ ⋯)
        (𝟙 X) (𝟙 ((diagonalCover f 𝒰 𝒱).X ⟨i, (j, j)⟩)) (𝟙 (pullback.diagonalObj f)) ⋯ ⋯ ≫
      (pullbackDiagonalMapIso f (𝒰.f i) ((𝒱 i).f j) ((𝒱 i).f j)).hom =
    (pullback.snd (pullback.diagonal f) ((diagonalCover f 𝒰 𝒱).f ⟨i, (j, j)⟩) ≫
        pullback.fst ((𝒱 i).f j ≫ pullback.snd f (𝒰.f i)) ((𝒱 i).f j ≫ pullback.snd f (𝒰.f i))) ≫
      pullback.diagonal ((𝒱 i).f j)

Tactic:
apply pullback.hom_ext <;> simp [H]

Goal state after:
Module: Mathlib.AlgebraicGeometry.Pullbacks

Goal state before:
pp: case h₁
X Y Z : Scheme
𝒰✝ : X.OpenCover
f✝ : X ⟶ Z
g : Y ⟶ Z
inst✝ : ∀ (i : 𝒰✝.I₀), HasPullback (𝒰✝.f i ≫ f✝) g
s : PullbackCone f✝ g
f : X ⟶ Y
𝒰 : Y.OpenCover
𝒱 : (i : (Precoverage.ZeroHypercover.pullback₁ f 𝒰).I₀) → ((Precoverage.ZeroHypercover.pullback₁ f 𝒰).X i).OpenCover
i : (openCoverOfBase 𝒰 f f).I₀
j : (𝒱 i).I₀
H :
  pullback.snd (pullback.diagonal f) ((diagonalCover f 𝒰 𝒱).f ⟨i, (j, j)⟩) ≫
      pullback.snd ((𝒱 i).f j ≫ pullback.snd f (𝒰.f i)) ((𝒱 i).f j ≫ pullback.snd f (𝒰.f i)) =
    pullback.snd (pullback.diagonal f) ((diagonalCover f 𝒰 𝒱).f ⟨i, (j, j)⟩) ≫
      pullback.fst ((𝒱 i).f j ≫ pullback.snd f (𝒰.f i)) ((𝒱 i).f j ≫ pullback.snd f (𝒰.f i))
⊢ pullback.map (pullback.diagonal f) ((diagonalCover f 𝒰 𝒱).f ⟨i, (j, j)⟩) (pullback.diagonal f)
        (pullback.map ((𝒱 i).f j ≫ pullback.snd f (𝒰.f i)) ((𝒱 i).f j ≫ pullback.snd f (𝒰.f i)) f f
          ((𝒱 i).f j ≫ pullback.fst f (𝒰.f i)) ((𝒱 i).f j ≫ pullback.fst f (𝒰.f i)) (𝒰.f i) ⋯ ⋯)
        (𝟙 X) (𝟙 ((diagonalCover f 𝒰 𝒱).X ⟨i, (j, j)⟩)) (𝟙 (pullback.diagonalObj f)) ⋯ ⋯ ≫
      (pullbackDiagonalMapIso f (𝒰.f i) ((𝒱 i).f j) ((𝒱 i).f j)).hom =
    (pullback.snd (pullback.diagonal f) ((diagonalCover f 𝒰 𝒱).f ⟨i, (j, j)⟩) ≫
        pullback.snd ((𝒱 i).f j ≫ pullback.snd f (𝒰.f i)) ((𝒱 i).f j ≫ pullback.snd f (𝒰.f i))) ≫
      pullback.diagonal ((𝒱 i).f j)

Tactic:
apply pullback.hom_ext <;> simp [H]

Goal state after:
Module: Mathlib.RingTheory.RingHom.Locally

Goal state before:
pp: case refine_2
P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hPl : LocalizationAwayPreserves fun {R S} [CommRing R] [CommRing S] ↦ P
R S : Type u
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
f : R →+* S
r : R
R' S' : Type u
inst✝⁵ : CommRing R'
inst✝⁴ : CommRing S'
inst✝³ : Algebra R R'
inst✝² : Algebra S S'
inst✝¹ : IsLocalization.Away r R'
inst✝ : IsLocalization.Away (f r) S'
s : Set S
hsone : Ideal.span s = ⊤
hs : ∀ t ∈ s, (fun {R S} [CommRing R] [CommRing S] ↦ P) ((algebraMap S (Localization.Away t)).comp f)
rₐ : (a : ↑s) → Localization.Away ↑a := fun a ↦ (algebraMap S (Localization.Away ↑a)) (f r)
Sₐ : ↑s → Type u := fun a ↦ Localization.Away (rₐ a)
this✝² : ∀ (a : ↑s), IsLocalization.Away (((algebraMap S (Localization.Away ↑a)).comp f) r) (Sₐ a)
this✝¹ :
  ∀ (a : ↑s),
    IsLocalization (Algebra.algebraMapSubmonoid (Localization.Away ↑a) (Submonoid.map f (Submonoid.powers r))) (Sₐ a)
H : ∀ (a : ↑s), Submonoid.powers (f r) ≤ Submonoid.comap (algebraMap S (Localization.Away ↑a)) (Submonoid.powers (rₐ a))
this✝ : (a : ↑s) → Algebra S' (Sₐ a) :=
  fun a ↦ (IsLocalization.map (Sₐ a) (algebraMap S (Localization.Away ↑a)) ⋯).toAlgebra
this : ∀ (a : ↑s), IsScalarTower S S' (Sₐ a)
a : ↑s
⊢ IsLocalization.Away ((fun a ↦ (algebraMap S S') ↑a) a) (Sₐ a)

Tactic:
convert!
    IsLocalization.commutes (T := Sₐ a) (M₁ := (Submonoid.powers r).map f) (S₁ := S') (S₂ :=
      Localization.Away a.val) (M₂ := Submonoid.powers a.val)
    simp [Algebra.algebraMapSubmonoid]

Goal state after: