-- Mathlib/Algebra/Category/ModuleCat/Presheaf/Sheafify.lean
protected lemma add_smul : smul α φ (r + r') m = smul α φ r m + smul α φ r' m

Proof state:
C : Type u₁
inst✝⁴ : Category.{v₁, u₁} C
J : GrothendieckTopology C
R₀ : Cᵒᵖ ⥤ RingCat
R : Sheaf J RingCat
α : R₀ ⟶ R.val
inst✝³ : Presheaf.IsLocallyInjective J α
inst✝² : Presheaf.IsLocallySurjective J α
M₀ : PresheafOfModules R₀
A : Sheaf J AddCommGrp
φ : M₀.presheaf ⟶ A.val
inst✝¹ : Presheaf.IsLocallyInjective J φ
inst✝ : Presheaf.IsLocallySurjective J φ
X : Cᵒᵖ
r r' : ↑(R.val.obj X)
m : ↑(A.val.obj X)
S : Sieve (Opposite.unop X) := Presheaf.imageSieve α r ⊓ Presheaf.imageSieve α r' ⊓ Presheaf.imageSieve φ m
hS : S ∈ J (Opposite.unop X)
Y : C
f : Y ⟶ Opposite.unop X
r₀ : ↑(R₀.obj (Opposite.op Y))
hr₀ : (ConcreteCategory.hom (α.app (Opposite.op Y))) r₀ = (ConcreteCategory.hom (R.val.map f.op)) r
r₀' : ↑(R₀.obj (Opposite.op Y))
hr₀' : (ConcreteCategory.hom (α.app (Opposite.op Y))) r₀' = (ConcreteCategory.hom (R.val.map f.op)) r'
m₀ : ToType (M₀.presheaf.obj (Opposite.op Y))
hm₀ : (ConcreteCategory.hom (φ.app (Opposite.op Y))) m₀ = (ConcreteCategory.hom (A.val.map f.op)) m
⊢ (ConcreteCategory.hom (α.app (Opposite.op Y))) (r₀ + r₀') = (ConcreteCategory.hom (R.val.map f.op)) (r + r')

Tactic:
rw [map_add, map_add, hr₀, hr₀']

Result:
no goals

Proof state:
C : Type u₁
inst✝⁴ : Category.{v₁, u₁} C
J : GrothendieckTopology C
R₀ : Cᵒᵖ ⥤ RingCat
R : Sheaf J RingCat
α : R₀ ⟶ R.val
inst✝³ : Presheaf.IsLocallyInjective J α
inst✝² : Presheaf.IsLocallySurjective J α
M₀ : PresheafOfModules R₀
A : Sheaf J AddCommGrp
φ : M₀.presheaf ⟶ A.val
inst✝¹ : Presheaf.IsLocallyInjective J φ
inst✝ : Presheaf.IsLocallySurjective J φ
X : Cᵒᵖ
r r' : ↑(R.val.obj X)
m : ↑(A.val.obj X)
S : Sieve (Opposite.unop X) := Presheaf.imageSieve α r ⊓ Presheaf.imageSieve α r' ⊓ Presheaf.imageSieve φ m
⊢ smul α φ (r + r') m = smul α φ r m + smul α φ r' m

Tactic:
have hS : S ∈ J X.unop := by
  refine J.intersection_covering (J.intersection_covering ?_ ?_) ?_
  all_goals apply Presheaf.imageSieve_mem

Result:
C : Type u₁
inst✝⁴ : Category.{v₁, u₁} C
J : GrothendieckTopology C
R₀ : Cᵒᵖ ⥤ RingCat
R : Sheaf J RingCat
α : R₀ ⟶ R.val
inst✝³ : Presheaf.IsLocallyInjective J α
inst✝² : Presheaf.IsLocallySurjective J α
M₀ : PresheafOfModules R₀
A : Sheaf J AddCommGrp
φ : M₀.presheaf ⟶ A.val
inst✝¹ : Presheaf.IsLocallyInjective J φ
inst✝ : Presheaf.IsLocallySurjective J φ
X : Cᵒᵖ
r r' : ↑(R.val.obj X)
m : ↑(A.val.obj X)
S : Sieve (Opposite.unop X) := Presheaf.imageSieve α r ⊓ Presheaf.imageSieve α r' ⊓ Presheaf.imageSieve φ m
hS : S ∈ J (Opposite.unop X)
⊢ smul α φ (r + r') m = smul α φ r m + smul α φ r' m

Proof state:
case a
C : Type u₁
inst✝⁴ : Category.{v₁, u₁} C
J : GrothendieckTopology C
R₀ : Cᵒᵖ ⥤ RingCat
R : Sheaf J RingCat
α : R₀ ⟶ R.val
inst✝³ : Presheaf.IsLocallyInjective J α
inst✝² : Presheaf.IsLocallySurjective J α
M₀ : PresheafOfModules R₀
A : Sheaf J AddCommGrp
φ : M₀.presheaf ⟶ A.val
inst✝¹ : Presheaf.IsLocallyInjective J φ
inst✝ : Presheaf.IsLocallySurjective J φ
X : Cᵒᵖ
r r' : ↑(R.val.obj X)
m : ↑(A.val.obj X)
S : Sieve (Opposite.unop X) := Presheaf.imageSieve α r ⊓ Presheaf.imageSieve α r' ⊓ Presheaf.imageSieve φ m
hS : S ∈ J (Opposite.unop X)
⊢ ∀ (Y : C) (f : Y ⟶ Opposite.unop X),
    S.arrows f →
      (ConcreteCategory.hom (A.val.map f.op)) (smul α φ (r + r') m) =
        (ConcreteCategory.hom (A.val.map f.op)) (smul α φ r m + smul α φ r' m)

Tactic:
rintro Y f ⟨⟨⟨r₀ : R₀.obj _, (hr₀ : (α.app (Opposite.op Y)) r₀ = (R.val.map f.op) r)⟩,
  ⟨r₀' : R₀.obj _, (hr₀' : (α.app (Opposite.op Y)) r₀' = (R.val.map f.op) r')⟩⟩, ⟨m₀, hm₀⟩⟩

Result:
case a.intro.intro.intro.intro.intro
C : Type u₁
inst✝⁴ : Category.{v₁, u₁} C
J : GrothendieckTopology C
R₀ : Cᵒᵖ ⥤ RingCat
R : Sheaf J RingCat
α : R₀ ⟶ R.val
inst✝³ : Presheaf.IsLocallyInjective J α
inst✝² : Presheaf.IsLocallySurjective J α
M₀ : PresheafOfModules R₀
A : Sheaf J AddCommGrp
φ : M₀.presheaf ⟶ A.val
inst✝¹ : Presheaf.IsLocallyInjective J φ
inst✝ : Presheaf.IsLocallySurjective J φ
X : Cᵒᵖ
r r' : ↑(R.val.obj X)
m : ↑(A.val.obj X)
S : Sieve (Opposite.unop X) := Presheaf.imageSieve α r ⊓ Presheaf.imageSieve α r' ⊓ Presheaf.imageSieve φ m
hS : S ∈ J (Opposite.unop X)
Y : C
f : Y ⟶ Opposite.unop X
r₀ : ↑(R₀.obj (Opposite.op Y))
hr₀ : (ConcreteCategory.hom (α.app (Opposite.op Y))) r₀ = (ConcreteCategory.hom (R.val.map f.op)) r
r₀' : ↑(R₀.obj (Opposite.op Y))
hr₀' : (ConcreteCategory.hom (α.app (Opposite.op Y))) r₀' = (ConcreteCategory.hom (R.val.map f.op)) r'
m₀ : ToType (M₀.presheaf.obj (Opposite.op Y))
hm₀ : (ConcreteCategory.hom (φ.app (Opposite.op Y))) m₀ = (ConcreteCategory.hom (A.val.map f.op)) m
⊢ (ConcreteCategory.hom (A.val.map f.op)) (smul α φ (r + r') m) =
    (ConcreteCategory.hom (A.val.map f.op)) (smul α φ r m + smul α φ r' m)

Proof state:
case refine_1
C : Type u₁
inst✝⁴ : Category.{v₁, u₁} C
J : GrothendieckTopology C
R₀ : Cᵒᵖ ⥤ RingCat
R : Sheaf J RingCat
α : R₀ ⟶ R.val
inst✝³ : Presheaf.IsLocallyInjective J α
inst✝² : Presheaf.IsLocallySurjective J α
M₀ : PresheafOfModules R₀
A : Sheaf J AddCommGrp
φ : M₀.presheaf ⟶ A.val
inst✝¹ : Presheaf.IsLocallyInjective J φ
inst✝ : Presheaf.IsLocallySurjective J φ
X : Cᵒᵖ
r r' : ↑(R.val.obj X)
m : ↑(A.val.obj X)
S : Sieve (Opposite.unop X) := Presheaf.imageSieve α r ⊓ Presheaf.imageSieve α r' ⊓ Presheaf.imageSieve φ m
⊢ Presheaf.imageSieve α r ∈ J (Opposite.unop X)

case refine_2
C : Type u₁
inst✝⁴ : Category.{v₁, u₁} C
J : GrothendieckTopology C
R₀ : Cᵒᵖ ⥤ RingCat
R : Sheaf J RingCat
α : R₀ ⟶ R.val
inst✝³ : Presheaf.IsLocallyInjective J α
inst✝² : Presheaf.IsLocallySurjective J α
M₀ : PresheafOfModules R₀
A : Sheaf J AddCommGrp
φ : M₀.presheaf ⟶ A.val
inst✝¹ : Presheaf.IsLocallyInjective J φ
inst✝ : Presheaf.IsLocallySurjective J φ
X : Cᵒᵖ
r r' : ↑(R.val.obj X)
m : ↑(A.val.obj X)
S : Sieve (Opposite.unop X) := Presheaf.imageSieve α r ⊓ Presheaf.imageSieve α r' ⊓ Presheaf.imageSieve φ m
⊢ Presheaf.imageSieve α r' ∈ J (Opposite.unop X)

case refine_3
C : Type u₁
inst✝⁴ : Category.{v₁, u₁} C
J : GrothendieckTopology C
R₀ : Cᵒᵖ ⥤ RingCat
R : Sheaf J RingCat
α : R₀ ⟶ R.val
inst✝³ : Presheaf.IsLocallyInjective J α
inst✝² : Presheaf.IsLocallySurjective J α
M₀ : PresheafOfModules R₀
A : Sheaf J AddCommGrp
φ : M₀.presheaf ⟶ A.val
inst✝¹ : Presheaf.IsLocallyInjective J φ
inst✝ : Presheaf.IsLocallySurjective J φ
X : Cᵒᵖ
r r' : ↑(R.val.obj X)
m : ↑(A.val.obj X)
S : Sieve (Opposite.unop X) := Presheaf.imageSieve α r ⊓ Presheaf.imageSieve α r' ⊓ Presheaf.imageSieve φ m
⊢ Presheaf.imageSieve φ m ∈ J (Opposite.unop X)

Tactic:
all_goals apply Presheaf.imageSieve_mem

Result:
no goals