mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.LinearAlgebra.SesquilinearForm.Basic

Goal state before:
pp: R : Type u_1
R₁ : Type u_2
M : Type u_5
M₁ : Type u_6
inst✝⁵ : CommSemiring R
inst✝⁴ : AddCommMonoid M
inst✝³ : Module R M
inst✝² : CommSemiring R₁
inst✝¹ : AddCommMonoid M₁
inst✝ : Module R₁ M₁
I₁ I₂ : R₁ →+* R
B : M₁ →ₛₗ[I₁] M₁ →ₛₗ[I₂] M
H : B.IsRefl
p : Submodule R₁ M₁
x✝¹ x✝ : ↥p
⊢ ((B.domRestrict₁₂ p p) x✝¹) x✝ = 0 → ((B.domRestrict₁₂ p p) x✝) x✝¹ = 0

Tactic:
domRestrict₁₂_apply

Goal state after:
R : Type u_1
R₁ : Type u_2
M : Type u_5
M₁ : Type u_6
inst✝⁵ : CommSemiring R
inst✝⁴ : AddCommMonoid M
inst✝³ : Module R M
inst✝² : CommSemiring R₁
inst✝¹ : AddCommMonoid M₁
inst✝ : Module R₁ M₁
I₁ I₂ : R₁ →+* R
B : M₁ →ₛₗ[I₁] M₁ →ₛₗ[I₂] M
H : B.IsRefl
p : Submodule R₁ M₁
x✝¹ x✝ : ↥p
⊢ (B ↑x✝¹) ↑x✝ = 0 → (B ↑x✝) ↑x✝¹ = 0
Module: Mathlib.LinearAlgebra.SesquilinearForm.Basic

Goal state before:
pp: R : Type u_1
M : Type u_5
inst✝² : CommSemiring R
inst✝¹ : AddCommMonoid M
inst✝ : Module R M
I : R →+* R
B : M →ₛₗ[I] M →ₗ[R] R
H : B.IsSymm
p : Submodule R M
x✝¹ x✝ : ↥p
⊢ I (((B.domRestrict₁₂ p p) x✝¹) x✝) = ((B.domRestrict₁₂ p p) x✝) x✝¹

Tactic:
domRestrict₁₂_apply

Goal state after:
R : Type u_1
M : Type u_5
inst✝² : CommSemiring R
inst✝¹ : AddCommMonoid M
inst✝ : Module R M
I : R →+* R
B : M →ₛₗ[I] M →ₗ[R] R
H : B.IsSymm
p : Submodule R M
x✝¹ x✝ : ↥p
⊢ I ((B ↑x✝¹) ↑x✝) = (B ↑x✝) ↑x✝¹
Module: Mathlib.LinearAlgebra.Contraction

Goal state before:
pp: ι : Type u_1
R : Type u_2
M : Type u_3
N : Type u_4
P : Type u_5
Q : Type u_6
inst✝¹⁰ : CommSemiring R
inst✝⁹ : AddCommMonoid M
inst✝⁸ : AddCommMonoid N
inst✝⁷ : AddCommMonoid P
inst✝⁶ : AddCommMonoid Q
inst✝⁵ : Module R M
inst✝⁴ : Module R N
inst✝³ : Module R P
inst✝² : Module R Q
b : Basis ι R M
inst✝¹ : DecidableEq ι
inst✝ : Fintype ι
⊢ dualTensorHom R M N ∘ₗ ∑ i, (TensorProduct.mk R (Dual R M) N) (b.dualBasis i) ∘ₗ applyₗ (b i) = LinearMap.id

Tactic:
by
      ext f m
      simp only [applyₗ_apply_apply, coe_sum, dualTensorHom_apply, mk_apply, id_coe, _root_.id,
        Fintype.sum_apply, Function.comp_apply, Basis.coe_dualBasis, coe_comp, Basis.coord_apply, ←
        f.map_smul, _root_.map_sum (dualTensorHom R M N), ← _root_.map_sum f, b.sum_repr]

Goal state after:
Module: Mathlib.LinearAlgebra.SesquilinearForm.Basic

Goal state before:
pp: R : Type u_1
M : Type u_5
M₁ : Type u_6
inst✝⁴ : CommRing R
inst✝³ : AddCommGroup M
inst✝² : Module R M
inst✝¹ : AddCommGroup M₁
inst✝ : Module R M₁
B : M →ₗ[R] M →ₗ[R] M₁
W : Submodule R M
hW : (B.domRestrict₁₂ W W).Nondegenerate
x : M
hx : x ∈ W
hx' : x ∈ B.ker
x' : ↥W := ⟨x, hx⟩
⊢ ∀ (a : M) (b : a ∈ W), ((B.domRestrict₁₂ W W) x') ⟨a, b⟩ = 0

Tactic:
domRestrict₁₂_apply

Goal state after:
R : Type u_1
M : Type u_5
M₁ : Type u_6
inst✝⁴ : CommRing R
inst✝³ : AddCommGroup M
inst✝² : Module R M
inst✝¹ : AddCommGroup M₁
inst✝ : Module R M₁
B : M →ₗ[R] M →ₗ[R] M₁
W : Submodule R M
hW : (B.domRestrict₁₂ W W).Nondegenerate
x : M
hx : x ∈ W
hx' : x ∈ B.ker
x' : ↥W := ⟨x, hx⟩
⊢ ∀ a ∈ W, (B ↑x') a = 0
Module: Mathlib.LinearAlgebra.SesquilinearForm.Basic

Goal state before:
pp: R : Type u_1
M : Type u_5
M₁ : Type u_6
inst✝⁴ : CommRing R
inst✝³ : AddCommGroup M
inst✝² : Module R M
inst✝¹ : AddCommGroup M₁
inst✝ : Module R M₁
B : M →ₗ[R] M →ₗ[R] M₁
W : Submodule R M
hW : (B.domRestrict₁₂ W W).Nondegenerate
x : M
hx : x ∈ W
hx' : x ∈ B.ker
x' : ↥W := ⟨x, hx⟩
⊢ ∀ a ∈ W, (B ↑x') a = 0

Tactic:
intro y hy

Goal state after:
R : Type u_1
M : Type u_5
M₁ : Type u_6
inst✝⁴ : CommRing R
inst✝³ : AddCommGroup M
inst✝² : Module R M
inst✝¹ : AddCommGroup M₁
inst✝ : Module R M₁
B : M →ₗ[R] M →ₗ[R] M₁
W : Submodule R M
hW : (B.domRestrict₁₂ W W).Nondegenerate
x : M
hx : x ∈ W
hx' : x ∈ B.ker
x' : ↥W := ⟨x, hx⟩
y : M
hy : y ∈ W
⊢ (B ↑x') y = 0
Module: Mathlib.LinearAlgebra.SesquilinearForm.Basic

Goal state before:
pp: n : Type u_19
R : Type u_20
M : Type u_21
M₁ : Type u_22
inst✝⁵ : CommSemiring R
inst✝⁴ : AddCommMonoid M
inst✝³ : AddCommMonoid M₁
inst✝² : Module R M
inst✝¹ : Module R M₁
I I' : R →+* R
B : M →ₛₗ[I] M →ₛₗ[I'] M₁
inst✝ : Nontrivial R
v : Basis n R M
h : B.IsOrthoᵢ ⇑v
hB : B.SeparatingLeft
i : n
⊢ (B (v i)) (v i) ≠ 0

Tactic:
intro ho

Goal state after:
n : Type u_19
R : Type u_20
M : Type u_21
M₁ : Type u_22
inst✝⁵ : CommSemiring R
inst✝⁴ : AddCommMonoid M
inst✝³ : AddCommMonoid M₁
inst✝² : Module R M
inst✝¹ : Module R M₁
I I' : R →+* R
B : M →ₛₗ[I] M →ₛₗ[I'] M₁
inst✝ : Nontrivial R
v : Basis n R M
h : B.IsOrthoᵢ ⇑v
hB : B.SeparatingLeft
i : n
ho : (B (v i)) (v i) = 0
⊢ False
Module: Mathlib.CategoryTheory.Limits.Shapes.SplitEqualizer

Goal state before:
pp: C : Type u
inst✝¹ : Category.{v, u} C
D : Type u₂
inst✝ : Category.{v₂, u₂} D
G : C ⥤ D
X Y : C
f g : X ⟶ Y
W : C
ι : W ⟶ X
q : IsSplitEqualizer f g ι
F : C ⥤ D
⊢ F.map g ≫ F.map q.rightRetraction = 𝟙 (F.obj X)

Tactic:
by rw [← F.map_comp, q.bottom_rightRetraction, F.map_id]

Goal state after:
Module: Mathlib.LinearAlgebra.Dual.Lemmas

Goal state before:
pp: R : Type u_1
M : Type u_2
inst✝³ : CommRing R
inst✝² : AddCommGroup M
inst✝¹ : Module R M
inst✝ : Projective R M
⊢ comap (Dual.eval R M) ⊤.dualAnnihilator = ⊥

Tactic:
dualAnnihilator_top,

Goal state after:
R : Type u_1
M : Type u_2
inst✝³ : CommRing R
inst✝² : AddCommGroup M
inst✝¹ : Module R M
inst✝ : Projective R M
⊢ comap (Dual.eval R M) ⊥ = ⊥
Module: Mathlib.CategoryTheory.Limits.Preserves.Shapes.Equalizers

Goal state before:
pp: case a
C : Type u₁
inst✝⁵ : Category.{v₁, u₁} C
D : Type u₂
inst✝⁴ : Category.{v₂, u₂} D
G : C ⥤ D
X Y : C
f g : X ⟶ Y
inst✝³ : HasCoequalizer f g
inst✝² : HasCoequalizer (G.map f) (G.map g)
inst✝¹ : PreservesColimit (parallelPair f g) G
X' Y' : D
f' g' : X' ⟶ Y'
inst✝ : HasCoequalizer f' g'
p : G.obj X ⟶ X'
q : G.obj Y ⟶ Y'
wf : G.map f ≫ q = p ≫ f'
wg : G.map g ≫ q = p ≫ g'
Z' : D
h : Y' ⟶ Z'
wh : f' ≫ h = g' ≫ h
| G.map (coequalizer.π f g) ≫
    (PreservesCoequalizer.iso G f g).inv ≫ colimMap (parallelPairHom (G.map f) (G.map g) f' g' p q wf wg)

pp: case a
C : Type u₁
inst✝⁵ : Category.{v₁, u₁} C
D : Type u₂
inst✝⁴ : Category.{v₂, u₂} D
G : C ⥤ D
X Y : C
f g : X ⟶ Y
inst✝³ : HasCoequalizer f g
inst✝² : HasCoequalizer (G.map f) (G.map g)
inst✝¹ : PreservesColimit (parallelPair f g) G
X' Y' : D
f' g' : X' ⟶ Y'
inst✝ : HasCoequalizer f' g'
p : G.obj X ⟶ X'
q : G.obj Y ⟶ Y'
wf : G.map f ≫ q = p ≫ f'
wg : G.map g ≫ q = p ≫ g'
Z' : D
h : Y' ⟶ Z'
wh : f' ≫ h = g' ≫ h
| coequalizer.desc h wh

Tactic:
rw [map_π_preserves_coequalizer_inv_colimMap]

Goal state after:
case a
C : Type u₁
inst✝⁵ : Category.{v₁, u₁} C
D : Type u₂
inst✝⁴ : Category.{v₂, u₂} D
G : C ⥤ D
X Y : C
f g : X ⟶ Y
inst✝³ : HasCoequalizer f g
inst✝² : HasCoequalizer (G.map f) (G.map g)
inst✝¹ : PreservesColimit (parallelPair f g) G
X' Y' : D
f' g' : X' ⟶ Y'
inst✝ : HasCoequalizer f' g'
p : G.obj X ⟶ X'
q : G.obj Y ⟶ Y'
wf : G.map f ≫ q = p ≫ f'
wg : G.map g ≫ q = p ≫ g'
Z' : D
h : Y' ⟶ Z'
wh : f' ≫ h = g' ≫ h
| q ≫ coequalizer.π f' g'

case a
C : Type u₁
inst✝⁵ : Category.{v₁, u₁} C
D : Type u₂
inst✝⁴ : Category.{v₂, u₂} D
G : C ⥤ D
X Y : C
f g : X ⟶ Y
inst✝³ : HasCoequalizer f g
inst✝² : HasCoequalizer (G.map f) (G.map g)
inst✝¹ : PreservesColimit (parallelPair f g) G
X' Y' : D
f' g' : X' ⟶ Y'
inst✝ : HasCoequalizer f' g'
p : G.obj X ⟶ X'
q : G.obj Y ⟶ Y'
wf : G.map f ≫ q = p ≫ f'
wg : G.map g ≫ q = p ≫ g'
Z' : D
h : Y' ⟶ Z'
wh : f' ≫ h = g' ≫ h
| coequalizer.desc h wh
Module: Mathlib.LinearAlgebra.SesquilinearForm.Basic

Goal state before:
pp: R : Type u_1
M : Type u_5
inst✝⁴ : CommRing R
inst✝³ : LinearOrder R
inst✝² : IsStrictOrderedRing R
inst✝¹ : AddCommGroup M
inst✝ : Module R M
B : LinearMap.BilinForm R M
hs : ∀ (x : M), 0 ≤ (B x) x
hB : IsSymm B
W : Submodule R M
hW : Disjoint W (ker B)
hB' : (domRestrict₁₂ B W W).IsRefl
x : M
hx : x ∈ W
h : ∀ (a : M) (b : a ∈ W), ((domRestrict₁₂ B W W) ⟨x, hx⟩) ⟨a, b⟩ = 0
⊢ ⟨x, hx⟩ = 0

Tactic:
domRestrict₁₂_apply

Goal state after:
R : Type u_1
M : Type u_5
inst✝⁴ : CommRing R
inst✝³ : LinearOrder R
inst✝² : IsStrictOrderedRing R
inst✝¹ : AddCommGroup M
inst✝ : Module R M
B : LinearMap.BilinForm R M
hs : ∀ (x : M), 0 ≤ (B x) x
hB : IsSymm B
W : Submodule R M
hW : Disjoint W (ker B)
hB' : (domRestrict₁₂ B W W).IsRefl
x : M
hx : x ∈ W
h : ∀ a ∈ W, (B x) a = 0
⊢ ⟨x, hx⟩ = 0
Module: Mathlib.LinearAlgebra.Dual.Lemmas

Goal state before:
pp: K : Type u_3
V₁ : Type u_4
V₂ : Type u_5
inst✝⁴ : Field K
inst✝³ : AddCommGroup V₁
inst✝² : Module K V₁
inst✝¹ : AddCommGroup V₂
inst✝ : Module K V₂
f : V₁ →ₗ[K] V₂
⊢ Function.Surjective ⇑f.dualMap ↔ Function.Injective ⇑f

Tactic:
rw [← LinearMap.range_eq_top, range_dualMap_eq_dualAnnihilator_ker,
      ← Submodule.dualAnnihilator_bot, Subspace.dualAnnihilator_inj, LinearMap.ker_eq_bot]

Goal state after:
Module: Mathlib.CategoryTheory.Limits.Constructions.Pullbacks

Goal state before:
pp: C : Type u
𝒞 : Category.{v, u} C
X Y Z : C
f : X ⟶ Z
g : Y ⟶ Z
inst✝¹ : HasLimit (pair X Y)
inst✝ : HasLimit (parallelPair (prod.fst ≫ f) (prod.snd ≫ g))
π₁ : X ⨯ Y ⟶ X := prod.fst
π₂ : X ⨯ Y ⟶ Y := prod.snd
e : equalizer (π₁ ≫ f) (π₂ ≫ g) ⟶ X ⨯ Y := equalizer.ι (π₁ ≫ f) (π₂ ≫ g)
s : PullbackCone f g
m : s.pt ⟶ equalizer (π₁ ≫ f) (π₂ ≫ g)
h₁ : m ≫ e ≫ π₁ = s.fst
h₂ : m ≫ e ≫ π₂ = s.snd
⊢ m = equalizer.lift (prod.lift (s.π.app WalkingCospan.left) (s.π.app WalkingCospan.right)) ⋯

Tactic:
ext
          · simpa using h₁
          · simpa using h₂

Goal state after:
Module: Mathlib.LinearAlgebra.Dual.Lemmas

Goal state before:
pp: case of_equiv
K : Type u_1
V₁ : Type u_2
inst✝² : Field K
inst✝¹ : AddCommGroup V₁
inst✝ : Module K V₁
α β : Type u_4
h : α ≃ β
⊢ (∀ (W : α → Subspace K V₁), dualAnnihilator (⨅ i, W i) = ⨆ i, dualAnnihilator (W i)) →
    ∀ (W : β → Subspace K V₁), dualAnnihilator (⨅ i, W i) = ⨆ i, dualAnnihilator (W i)

Tactic:
hyp

Goal state after:
case of_equiv
K : Type u_1
V₁ : Type u_2
inst✝² : Field K
inst✝¹ : AddCommGroup V₁
inst✝ : Module K V₁
α β : Type u_4
h : α ≃ β
hyp : ∀ (W : α → Subspace K V₁), dualAnnihilator (⨅ i, W i) = ⨆ i, dualAnnihilator (W i)
⊢ ∀ (W : β → Subspace K V₁), dualAnnihilator (⨅ i, W i) = ⨆ i, dualAnnihilator (W i)
Module: Mathlib.CategoryTheory.Limits.Constructions.Pullbacks

Goal state before:
pp: C : Type u
𝒞 : Category.{v, u} C
X Y Z : C
f : X ⟶ Y
g : X ⟶ Z
inst✝¹ : HasColimit (pair Y Z)
inst✝ : HasColimit (parallelPair (f ≫ coprod.inl) (g ≫ coprod.inr))
ι₁ : Y ⟶ Y ⨿ Z := coprod.inl
ι₂ : Z ⟶ Y ⨿ Z := coprod.inr
c : Y ⨿ Z ⟶ coequalizer (f ≫ ι₁) (g ≫ ι₂) := coequalizer.π (f ≫ ι₁) (g ≫ ι₂)
s : PushoutCocone f g
m : coequalizer (f ≫ ι₁) (g ≫ ι₂) ⟶ s.pt
h₁ : (ι₁ ≫ c) ≫ m = s.inl
h₂ : (ι₂ ≫ c) ≫ m = s.inr
⊢ m = coequalizer.desc (coprod.desc (s.ι.app WalkingSpan.left) (s.ι.app WalkingSpan.right)) ⋯

Tactic:
ext
          · simpa using h₁
          · simpa using h₂

Goal state after:
Module: Mathlib.LinearAlgebra.Dual.Lemmas

Goal state before:
pp: K : Type u_1
V₁ : Type u_2
inst✝² : Field K
inst✝¹ : AddCommGroup V₁
inst✝ : Module K V₁
W W' : Subspace K V₁
h : W ⊓ W' = ⊥ ∧ W ⊔ W' = ⊤
⊢ dualAnnihilator ⊤ = ⊥ ∧ dualAnnihilator ⊥ = ⊤

Tactic:
dualAnnihilator_top,

Goal state after:
K : Type u_1
V₁ : Type u_2
inst✝² : Field K
inst✝¹ : AddCommGroup V₁
inst✝ : Module K V₁
W W' : Subspace K V₁
h : W ⊓ W' = ⊥ ∧ W ⊔ W' = ⊤
⊢ ⊥ = ⊥ ∧ dualAnnihilator ⊥ = ⊤
Module: Mathlib.CategoryTheory.Limits.Constructions.LimitsOfProductsAndEqualizers

Goal state before:
pp: C : Type u
inst✝⁸ : Category.{v, u} C
J : Type w
inst✝⁷ : SmallCategory J
D : Type u₂
inst✝⁶ : Category.{v₂, u₂} D
inst✝⁵ : HasColimitsOfShape (Discrete J) C
inst✝⁴ : HasColimitsOfShape (Discrete ((p : J × J) × (p.1 ⟶ p.2))) C
inst✝³ : HasCoequalizers C
G : C ⥤ D
inst✝² : PreservesColimitsOfShape WalkingParallelPair G
inst✝¹ : PreservesColimitsOfShape (Discrete J) G
inst✝ : PreservesColimitsOfShape (Discrete ((p : J × J) × (p.1 ⟶ p.2))) G
K : J ⥤ C
P : C := ⋯
Q : C := ⋯
s : Q ⟶ P := ⋯
t : Q ⟶ P := ⋯
I : C := ⋯
i : P ⟶ I := ⋯
⊢ IsColimit (Cofan.mk (G.obj Q) fun j ↦ G.map (Sigma.ι (fun j ↦ K.obj j.fst.1) j))

Tactic:
apply isColimitOfHasCoproductOfPreservesColimit

Goal state after:
Module: Mathlib.CategoryTheory.Limits.Constructions.LimitsOfProductsAndEqualizers

Goal state before:
pp: C : Type u
inst✝⁸ : Category.{v, u} C
J : Type w
inst✝⁷ : SmallCategory J
D : Type u₂
inst✝⁶ : Category.{v₂, u₂} D
inst✝⁵ : HasColimitsOfShape (Discrete J) C
inst✝⁴ : HasColimitsOfShape (Discrete ((p : J × J) × (p.1 ⟶ p.2))) C
inst✝³ : HasCoequalizers C
G : C ⥤ D
inst✝² : PreservesColimitsOfShape WalkingParallelPair G
inst✝¹ : PreservesColimitsOfShape (Discrete J) G
inst✝ : PreservesColimitsOfShape (Discrete ((p : J × J) × (p.1 ⟶ p.2))) G
K : J ⥤ C
P : C := ⋯
Q : C := ⋯
s : Q ⟶ P := ⋯
t : Q ⟶ P := ⋯
I : C := ⋯
i : P ⟶ I := ⋯
⊢ IsColimit (Cofan.mk (G.obj (∐ K.obj)) fun f ↦ G.map (Sigma.ι K.obj f))

Tactic:
apply isColimitOfHasCoproductOfPreservesColimit

Goal state after:
Module: Mathlib.CategoryTheory.Abelian.NonPreadditive

Goal state before:
pp: C : Type u
inst✝¹ : Category.{v, u} C
inst✝ : NonPreadditiveAbelian C
P Q : C
f : P ⟶ Q
I : C := Abelian.coimage f
i : Abelian.coimage f ⟶ Q := Abelian.factorThruCoimage f
p : P ⟶ cokernel (kernel.ι f) := cokernel.π (kernel.ι f)
R : C
g : R ⟶ I
hgi : g ≫ i = 0
u : P ⟶ cokernel g := p ≫ cokernel.π g
hu : NormalEpi u
h : NormalEpi.W u ⟶ P := NormalEpi.g
t : cokernel g ⟶ Q
ht : cokernel.π g ≫ t = i
hf : h ≫ f = 0
⊢ g = 0

Tactic:
obtain ⟨l, hl⟩ := kernel.lift' f h hf

Goal state after:
C : Type u
inst✝¹ : Category.{v, u} C
inst✝ : NonPreadditiveAbelian C
P Q : C
f : P ⟶ Q
I : C := Abelian.coimage f
i : Abelian.coimage f ⟶ Q := Abelian.factorThruCoimage f
p : P ⟶ cokernel (kernel.ι f) := cokernel.π (kernel.ι f)
R : C
g : R ⟶ I
hgi : g ≫ i = 0
u : P ⟶ cokernel g := p ≫ cokernel.π g
hu : NormalEpi u
h : NormalEpi.W u ⟶ P := NormalEpi.g
t : cokernel g ⟶ Q
ht : cokernel.π g ≫ t = i
hf : h ≫ f = 0
l : NormalEpi.W u ⟶ kernel f
hl : l ≫ kernel.ι f = h
⊢ g = 0
Module: Mathlib.CategoryTheory.Abelian.NonPreadditive

Goal state before:
pp: C : Type u
inst✝¹ : Category.{v, u} C
inst✝ : NonPreadditiveAbelian C
P Q : C
f : P ⟶ Q
I : C := Abelian.coimage f
i : Abelian.coimage f ⟶ Q := Abelian.factorThruCoimage f
p : P ⟶ cokernel (kernel.ι f) := cokernel.π (kernel.ι f)
R : C
g : R ⟶ I
hgi : g ≫ i = 0
u : P ⟶ cokernel g := p ≫ cokernel.π g
hu : NormalEpi u
h : NormalEpi.W u ⟶ P := NormalEpi.g
t : cokernel g ⟶ Q
ht : cokernel.π g ≫ t = i
hf : h ≫ f = 0
l : NormalEpi.W u ⟶ kernel f
hl : l ≫ kernel.ι f = h
hhp : h ≫ p = 0
⊢ g = 0

Tactic:
obtain ⟨s, hs⟩ := NormalEpi.desc' u p hhp

Goal state after:
C : Type u
inst✝¹ : Category.{v, u} C
inst✝ : NonPreadditiveAbelian C
P Q : C
f : P ⟶ Q
I : C := Abelian.coimage f
i : Abelian.coimage f ⟶ Q := Abelian.factorThruCoimage f
p : P ⟶ cokernel (kernel.ι f) := cokernel.π (kernel.ι f)
R : C
g : R ⟶ I
hgi : g ≫ i = 0
u : P ⟶ cokernel g := p ≫ cokernel.π g
hu : NormalEpi u
h : NormalEpi.W u ⟶ P := NormalEpi.g
t : cokernel g ⟶ Q
ht : cokernel.π g ≫ t = i
hf : h ≫ f = 0
l : NormalEpi.W u ⟶ kernel f
hl : l ≫ kernel.ι f = h
hhp : h ≫ p = 0
s : cokernel g ⟶ cokernel (kernel.ι f)
hs : u ≫ s = p
⊢ g = 0
Module: Mathlib.CategoryTheory.Abelian.Basic

Goal state before:
pp: C : Type u
inst✝³ : Category.{v, u} C
inst✝² : Abelian C
inst✝¹ : HasPullbacks C
W X Y Z : C
f : X ⟶ Z
g : Y ⟶ Z
inst✝ : Epi f
R : C
e : Y ⟶ R
h : pullback.snd f g ≫ e = 0
u : X ⊞ Y ⟶ R := biprod.desc 0 e
hu : PullbackToBiproductIsKernel.pullbackToBiproduct f g ≫ u = 0
this : IsColimit (CokernelCofork.ofπ (biprod.desc f (-g)) ⋯)
d : Z ⟶ R
hd : biprod.desc f (-g) ≫ d = biprod.desc 0 e
⊢ f ≫ d = (biprod.inl ≫ biprod.desc f (-g)) ≫ d

Tactic:
biprod.inl_desc

Goal state after:
C : Type u
inst✝³ : Category.{v, u} C
inst✝² : Abelian C
inst✝¹ : HasPullbacks C
W X Y Z : C
f : X ⟶ Z
g : Y ⟶ Z
inst✝ : Epi f
R : C
e : Y ⟶ R
h : pullback.snd f g ≫ e = 0
u : X ⊞ Y ⟶ R := biprod.desc 0 e
hu : PullbackToBiproductIsKernel.pullbackToBiproduct f g ≫ u = 0
this : IsColimit (CokernelCofork.ofπ (biprod.desc f (-g)) ⋯)
d : Z ⟶ R
hd : biprod.desc f (-g) ≫ d = biprod.desc 0 e
⊢ f ≫ d = f ≫ d
Module: Mathlib.CategoryTheory.Abelian.Basic

Goal state before:
pp: C : Type u
inst✝³ : Category.{v, u} C
inst✝² : Abelian C
inst✝¹ : HasPullbacks C
W X Y Z : C
f : X ⟶ Z
g : Y ⟶ Z
inst✝ : Epi g
R : C
e : X ⟶ R
h : pullback.fst f g ≫ e = 0
u : X ⊞ Y ⟶ R := biprod.desc e 0
hu : PullbackToBiproductIsKernel.pullbackToBiproduct f g ≫ u = 0
this✝¹ : IsColimit (CokernelCofork.ofπ (biprod.desc f (-g)) ⋯)
d : Z ⟶ R
hd : biprod.desc f (-g) ≫ d = biprod.desc e 0
this✝ : (-g) ≫ d = 0
this : d = 0
⊢ e = biprod.inl ≫ biprod.desc e 0

Tactic:
biprod.inl_desc

Goal state after:
C : Type u
inst✝³ : Category.{v, u} C
inst✝² : Abelian C
inst✝¹ : HasPullbacks C
W X Y Z : C
f : X ⟶ Z
g : Y ⟶ Z
inst✝ : Epi g
R : C
e : X ⟶ R
h : pullback.fst f g ≫ e = 0
u : X ⊞ Y ⟶ R := biprod.desc e 0
hu : PullbackToBiproductIsKernel.pullbackToBiproduct f g ≫ u = 0
this✝¹ : IsColimit (CokernelCofork.ofπ (biprod.desc f (-g)) ⋯)
d : Z ⟶ R
hd : biprod.desc f (-g) ≫ d = biprod.desc e 0
this✝ : (-g) ≫ d = 0
this : d = 0
⊢ e = e
Module: Mathlib.Algebra.Category.Grp.EpiMono

Goal state before:
pp: A B : CommGrpCat
f : A ⟶ B
⊢ Epi f ↔ Function.Surjective ⇑(ConcreteCategory.hom f)

Tactic:
epi_iff_range_eq_top,

Goal state after:
A B : CommGrpCat
f : A ⟶ B
⊢ (Hom.hom f).range = ⊤ ↔ Function.Surjective ⇑(ConcreteCategory.hom f)
Module: Mathlib.Algebra.Homology.ShortComplex.QuasiIso

Goal state before:
pp: C : Type u_1
inst✝³ : Category.{v_1, u_1} C
inst✝² : HasZeroMorphisms C
S₁ S₂ : ShortComplex C
inst✝¹ : S₁.HasHomology
inst✝ : S₂.HasHomology
φ : S₁ ⟶ S₂
⊢ QuasiIso (opMap φ) ↔ QuasiIso φ

Tactic:
have γ : HomologyMapData φ S₁.homologyData S₂.homologyData := default
  rw [γ.left.quasiIso_iff, γ.op.right.quasiIso_iff]
  dsimp
  constructor
  · intro h
    apply isIso_of_op
  · intro h
    infer_instance

Goal state after:
Module: Mathlib.Algebra.Homology.ShortComplex.RightHomology

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : HasZeroMorphisms C
S : ShortComplex C
h : S.RightHomologyData
hg : S.g = 0
⊢ 𝟙 h.Q ≫ h.g' = 0

Tactic:
by rw [← cancel_epi h.p, id_comp, p_g', comp_zero, hg]

Goal state after:
Module: Mathlib.Algebra.Homology.ShortComplex.Homology

Goal state before:
pp: C : Type u
inst✝¹ : Category.{v, u} C
inst✝ : HasZeroMorphisms C
S S₁ S₂ S₃ S₄ : ShortComplex C
φ : S₁ ⟶ S₂
h₁✝ : S₁.HomologyData
h₂✝ : S₂.HomologyData
h₁ : S.LeftHomologyData
h₂ : S.RightHomologyData
⊢ h₁.descH (h₁.i ≫ h₂.p) ⋯ ≫ h₂.g' = 0

Tactic:
rw [← cancel_epi h₁.π, LeftHomologyData.π_descH_assoc, assoc,
          RightHomologyData.p_g', LeftHomologyData.wi, comp_zero]

Goal state after:
Module: Mathlib.Algebra.Homology.ShortComplex.LeftHomology

Goal state before:
pp: C : Type u_1
inst✝⁴ : Category.{v_1, u_1} C
inst✝³ : HasZeroMorphisms C
S S₁ S₂ S₃ : ShortComplex C
φ : S₁ ⟶ S₂
h : S₁.LeftHomologyData
inst✝² : Epi φ.τ₁
inst✝¹ : IsIso φ.τ₂
inst✝ : Mono φ.τ₃
i : h.K ⟶ S₂.X₂ := h.i ≫ φ.τ₂
wi : i ≫ S₂.g = 0
W'✝ : C
x : W'✝ ⟶ S₂.X₂
hx : x ≫ S₂.g = 0
⊢ x ≫ inv φ.τ₂ ≫ S₁.g ≫ φ.τ₃ = 0 ≫ φ.τ₃

Tactic:
← φ.comm₂₃,

Goal state after:
C : Type u_1
inst✝⁴ : Category.{v_1, u_1} C
inst✝³ : HasZeroMorphisms C
S S₁ S₂ S₃ : ShortComplex C
φ : S₁ ⟶ S₂
h : S₁.LeftHomologyData
inst✝² : Epi φ.τ₁
inst✝¹ : IsIso φ.τ₂
inst✝ : Mono φ.τ₃
i : h.K ⟶ S₂.X₂ := h.i ≫ φ.τ₂
wi : i ≫ S₂.g = 0
W'✝ : C
x : W'✝ ⟶ S₂.X₂
hx : x ≫ S₂.g = 0
⊢ x ≫ inv φ.τ₂ ≫ φ.τ₂ ≫ S₂.g = 0 ≫ φ.τ₃
Module: Mathlib.Algebra.Homology.ShortComplex.Homology

Goal state before:
pp: C : Type u
inst✝² : Category.{v, u} C
inst✝¹ : HasZeroMorphisms C
S : ShortComplex C
inst✝ : S.HasHomology
⊢ S.leftRightHomologyComparison = S.leftHomologyIso.hom ≫ S.rightHomologyIso.inv

Tactic:
simpa only [LeftHomologyData.homologyIso_leftHomologyData, Iso.symm_inv,
    RightHomologyData.homologyIso_rightHomologyData, Iso.symm_hom] using!
      leftRightHomologyComparison'_fac S.leftHomologyData S.rightHomologyData

Goal state after:
Module: Mathlib.Algebra.Homology.ShortComplex.Homology

Goal state before:
pp: C : Type u
inst✝² : Category.{v, u} C
inst✝¹ : HasZeroMorphisms C
S : ShortComplex C
h : S.HomologyData
inst✝ : S.HasHomology
this : h.iso = h.left.homologyIso.symm ≪≫ h.right.homologyIso
⊢ h.right.homologyIso = h.left.homologyIso ≪≫ h.iso

Tactic:
rw [this, Iso.self_symm_id_assoc]

Goal state after:
Module: Mathlib.Algebra.Homology.ShortComplex.LeftHomology

Goal state before:
pp: C : Type u_1
inst✝⁴ : Category.{v_1, u_1} C
inst✝³ : HasZeroMorphisms C
S S₁ S₂ S₃ : ShortComplex C
φ : S₁ ⟶ S₂
h : S₂.LeftHomologyData
inst✝² : Epi φ.τ₁
inst✝¹ : IsIso φ.τ₂
inst✝ : Mono φ.τ₃
i : h.K ⟶ S₁.X₂ := h.i ≫ inv φ.τ₂
⊢ h.i ≫ inv φ.τ₂ ≫ S₁.g ≫ φ.τ₃ = 0

Tactic:
← φ.comm₂₃,

Goal state after:
C : Type u_1
inst✝⁴ : Category.{v_1, u_1} C
inst✝³ : HasZeroMorphisms C
S S₁ S₂ S₃ : ShortComplex C
φ : S₁ ⟶ S₂
h : S₂.LeftHomologyData
inst✝² : Epi φ.τ₁
inst✝¹ : IsIso φ.τ₂
inst✝ : Mono φ.τ₃
i : h.K ⟶ S₁.X₂ := h.i ≫ inv φ.τ₂
⊢ h.i ≫ inv φ.τ₂ ≫ φ.τ₂ ≫ S₂.g = 0
Module: Mathlib.Algebra.Homology.ShortComplex.RightHomology

Goal state before:
pp: C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : HasZeroMorphisms C
S : ShortComplex C
inst✝ : S.HasLeftHomology
⊢ S.op.pOpcycles ≫ S.opcyclesOpIso.hom = S.iCycles.op

Tactic:
dsimp [opcyclesOpIso]
  rw [← S.leftHomologyData.op.p_comp_opcyclesIso_inv, assoc,
    Iso.inv_hom_id, comp_id]
  rfl

Goal state after:
Module: Mathlib.Algebra.Homology.ShortComplex.Homology

Goal state before:
pp: C : Type u
inst✝² : Category.{v, u} C
inst✝¹ : HasZeroMorphisms C
S : ShortComplex C
A : C
inst✝ : S.HasHomology
k : S.X₂ ⟶ A
x : S.X₃ ⟶ A
hx : k = S.g ≫ x
⊢ S.homologyι ≫ S.descOpcycles k ⋯ = 0

Tactic:
dsimp only [homologyι]
  rw [assoc, S.rightHomologyι_descOpcycles_π_eq_zero_of_boundary k x hx, comp_zero]

Goal state after:
Module: Mathlib.Algebra.Homology.ShortComplex.LeftHomology

Goal state before:
pp: C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : HasZeroMorphisms C
S : ShortComplex C
h : S.LeftHomologyData
A : C
k : A ⟶ S.X₂
hk : k ≫ S.g = 0
inst✝ : S.HasLeftHomology
⊢ h.liftK k hk ≫ h.cyclesIso.inv = S.liftCycles k hk

Tactic:
rw [← h.liftCycles_comp_cyclesIso_hom, assoc, Iso.hom_inv_id, comp_id]

Goal state after:
Module: Mathlib.Algebra.Homology.ShortComplex.PreservesHomology

Goal state before:
pp: C : Type u_1
D : Type u_2
inst✝⁶ : Category.{v_1, u_1} C
inst✝⁵ : Category.{v_2, u_2} D
inst✝⁴ : HasZeroMorphisms C
inst✝³ : HasZeroMorphisms D
S S₁ S₂ : ShortComplex C
φ : S₁ ⟶ S₂
h₁ : S₁.LeftHomologyData
h₂ : S₂.LeftHomologyData
ψ : LeftHomologyMapData φ h₁ h₂
F : C ⥤ D
inst✝² : F.PreservesZeroMorphisms
inst✝¹ : h₁.IsPreservedBy F
inst✝ : h₂.IsPreservedBy F
⊢ (h₁.map F).π ≫ F.map ψ.φH = F.map ψ.φK ≫ (h₂.map F).π

Tactic:
by simpa only [F.map_comp] using! F.congr_map ψ.commπ

Goal state after:
Module: Mathlib.Algebra.Homology.ShortComplex.Limits

Goal state before:
pp: J : Type u_1
C : Type u_2
inst✝² : Category.{v_1, u_1} J
inst✝¹ : Category.{v_2, u_2} C
inst✝ : HasZeroMorphisms C
F : J ⥤ ShortComplex C
c : Cone F
h₁ : IsLimit (π₁.mapCone c)
h₂ : IsLimit (π₂.mapCone c)
h₃ : IsLimit (π₃.mapCone c)
s : Cone F
j : J
⊢ (h₁.lift (π₁.mapCone s) ≫ c.pt.f) ≫ (π₂.mapCone c).π.app j =
    (s.pt.f ≫ h₂.lift (π₂.mapCone s)) ≫ (π₂.mapCone c).π.app j

Tactic:
have eq₁ := h₁.fac (π₁.mapCone s)
        have eq₂ := h₂.fac (π₂.mapCone s)
        have eq₁₂ := fun j => (c.π.app j).comm₁₂
        have eq₁₂' := fun j => (s.π.app j).comm₁₂
        dsimp at eq₁ eq₂ eq₁₂ eq₁₂' ⊢
        rw [assoc, assoc, ← eq₁₂, reassoc_of% eq₁, eq₂, eq₁₂']

Goal state after:
Module: Mathlib.Algebra.Homology.ShortComplex.Preadditive

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : Preadditive C
S₁ S₂ S₃ : ShortComplex C
φ₁ φ₂ φ₃ φ₄ : S₁ ⟶ S₂
h : Homotopy φ₁ φ₂
⊢ φ₁.τ₁ = h.h₀ + S₁.f ≫ h.h₁ + φ₂.τ₁

Tactic:
rw [h.comm₁]

Goal state after:
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : Preadditive C
S₁ S₂ S₃ : ShortComplex C
φ₁ φ₂ φ₃ φ₄ : S₁ ⟶ S₂
h : Homotopy φ₁ φ₂
⊢ S₁.f ≫ h.h₁ + h.h₀ + φ₂.τ₁ = h.h₀ + S₁.f ≫ h.h₁ + φ₂.τ₁