mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Algebra.Homology.ShortComplex.Exact

Goal state before:
pp: case mp
C : Type u_1
D : Type u_2
inst✝⁸ : Category.{v_1, u_1} C
inst✝⁷ : Category.{v_2, u_2} D
inst✝⁶ : HasZeroMorphisms C
inst✝⁵ : HasZeroMorphisms D
S : ShortComplex C
inst✝⁴ : S.HasHomology
F : C ⥤ D
inst✝³ : F.PreservesZeroMorphisms
inst✝² : F.PreservesLeftHomologyOf S
inst✝¹ : F.PreservesRightHomologyOf S
inst✝ : F.Faithful
h : (S.map F).Exact
⊢ 𝟙 S.leftHomologyData.H = 0

Tactic:
]

Goal state after:
case mp
C : Type u_1
D : Type u_2
inst✝⁸ : Category.{v_1, u_1} C
inst✝⁷ : Category.{v_2, u_2} D
inst✝⁶ : HasZeroMorphisms C
inst✝⁵ : HasZeroMorphisms D
S : ShortComplex C
inst✝⁴ : S.HasHomology
F : C ⥤ D
inst✝³ : F.PreservesZeroMorphisms
inst✝² : F.PreservesLeftHomologyOf S
inst✝¹ : F.PreservesRightHomologyOf S
inst✝ : F.Faithful
h : (S.map F).Exact
⊢ 𝟙 S.leftHomologyData.H = 0
Module: Mathlib.Algebra.Homology.ShortComplex.Ab

Goal state before:
pp: S : ShortComplex Ab
hS : S.Exact
inst✝¹ : Finite ↑S.X₁
inst✝ : Finite ↑S.X₃
this : Finite ↥(AddCommGrpCat.Hom.hom S.f).range
⊢ Finite (↑S.X₂ ⧸ (AddCommGrpCat.Hom.hom S.g).ker)

Tactic:
]

Goal state after:
S : ShortComplex Ab
hS : S.Exact
inst✝¹ : Finite ↑S.X₁
inst✝ : Finite ↑S.X₃
this : Finite ↥(AddCommGrpCat.Hom.hom S.f).range
⊢ Finite (↑S.X₂ ⧸ (AddCommGrpCat.Hom.hom S.g).ker)
Module: Mathlib.Algebra.Homology.ShortComplex.Exact

Goal state before:
pp: case mp
C : Type u_1
D : Type u_2
inst✝⁸ : Category.{v_1, u_1} C
inst✝⁷ : Category.{v_2, u_2} D
inst✝⁶ : HasZeroMorphisms C
inst✝⁵ : HasZeroMorphisms D
S : ShortComplex C
inst✝⁴ : S.HasHomology
F : C ⥤ D
inst✝³ : F.PreservesZeroMorphisms
inst✝² : F.PreservesLeftHomologyOf S
inst✝¹ : F.PreservesRightHomologyOf S
inst✝ : F.Faithful
h : 𝟙 (F.obj S.leftHomologyData.H) = 0
⊢ 𝟙 S.leftHomologyData.H = 0

Tactic:
]

Goal state after:
case mp
C : Type u_1
D : Type u_2
inst✝⁸ : Category.{v_1, u_1} C
inst✝⁷ : Category.{v_2, u_2} D
inst✝⁶ : HasZeroMorphisms C
inst✝⁵ : HasZeroMorphisms D
S : ShortComplex C
inst✝⁴ : S.HasHomology
F : C ⥤ D
inst✝³ : F.PreservesZeroMorphisms
inst✝² : F.PreservesLeftHomologyOf S
inst✝¹ : F.PreservesRightHomologyOf S
inst✝ : F.Faithful
h : 𝟙 (F.obj S.leftHomologyData.H) = 0
⊢ 𝟙 S.leftHomologyData.H = 0
Module: Mathlib.Algebra.Homology.ShortComplex.Exact

Goal state before:
pp: case mp
C : Type u_1
D : Type u_2
inst✝⁸ : Category.{v_1, u_1} C
inst✝⁷ : Category.{v_2, u_2} D
inst✝⁶ : HasZeroMorphisms C
inst✝⁵ : HasZeroMorphisms D
S : ShortComplex C
inst✝⁴ : S.HasHomology
F : C ⥤ D
inst✝³ : F.PreservesZeroMorphisms
inst✝² : F.PreservesLeftHomologyOf S
inst✝¹ : F.PreservesRightHomologyOf S
inst✝ : F.Faithful
h : 𝟙 (F.obj S.leftHomologyData.H) = 0
⊢ 0 = 0

Tactic:
]

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

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : HasZeroMorphisms C
S : ShortComplex C
h : S.Exact
X Y : C
a : X ⟶ S.X₂
ha : a ≫ S.g = 0
b : S.X₂ ⟶ Y
hb : S.f ≫ b = 0
this : S.HasHomology
eq : S.iCycles ≫ S.pOpcycles = 0
⊢ a ≫ b = 0

Tactic:
]

Goal state after:
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : HasZeroMorphisms C
S : ShortComplex C
h : S.Exact
X Y : C
a : X ⟶ S.X₂
ha : a ≫ S.g = 0
b : S.X₂ ⟶ Y
hb : S.f ≫ b = 0
this : S.HasHomology
eq : S.iCycles ≫ S.pOpcycles = 0
⊢ a ≫ b = 0
Module: Mathlib.Algebra.Homology.ShortComplex.Exact

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : HasZeroMorphisms C
S : ShortComplex C
h : S.Exact
X Y : C
a : X ⟶ S.X₂
ha : a ≫ S.g = 0
b : S.X₂ ⟶ Y
hb : S.f ≫ b = 0
this : S.HasHomology
eq : S.iCycles ≫ S.pOpcycles = 0
⊢ S.liftCycles a ha ≫ S.iCycles ≫ S.pOpcycles ≫ S.descOpcycles b hb = 0

Tactic:
reassoc_of% eq,

Goal state after:
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : HasZeroMorphisms C
S : ShortComplex C
h : S.Exact
X Y : C
a : X ⟶ S.X₂
ha : a ≫ S.g = 0
b : S.X₂ ⟶ Y
hb : S.f ≫ b = 0
this : S.HasHomology
eq : S.iCycles ≫ S.pOpcycles = 0
⊢ S.liftCycles a ha ≫ 0 ≫ S.descOpcycles b hb = 0
Module: Mathlib.CategoryTheory.Adjunction.Reflective

Goal state before:
pp: C : Type u₁
D : Type u₂
inst✝² : Category.{v₁, u₁} C
inst✝¹ : Category.{v₂, u₂} D
i : D ⥤ C
inst✝ : Reflective i
X : C
⊢ (reflectorAdjunction i).unit.app (i.obj ((reflector i).obj X)) ≫
      i.map ((reflectorAdjunction i).counit.app ((reflector i).obj X)) =
    i.map
      ((reflector i).map ((reflectorAdjunction i).unit.app X) ≫
        (reflectorAdjunction i).counit.app ((reflector i).obj X))

Tactic:
]

Goal state after:
C : Type u₁
D : Type u₂
inst✝² : Category.{v₁, u₁} C
inst✝¹ : Category.{v₂, u₂} D
i : D ⥤ C
inst✝ : Reflective i
X : C
⊢ (reflectorAdjunction i).unit.app (i.obj ((reflector i).obj X)) ≫
      i.map ((reflectorAdjunction i).counit.app ((reflector i).obj X)) =
    i.map
      ((reflector i).map ((reflectorAdjunction i).unit.app X) ≫
        (reflectorAdjunction i).counit.app ((reflector i).obj X))
Module: Mathlib.Algebra.Homology.ShortComplex.Exact

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : HasZeroMorphisms C
S : ShortComplex C
h : S.Exact
X Y : C
a : X ⟶ S.X₂
ha : a ≫ S.g = 0
b : S.X₂ ⟶ Y
hb : S.f ≫ b = 0
this : S.HasHomology
eq : S.iCycles ≫ S.pOpcycles = 0
⊢ 0 = 0

Tactic:
]

Goal state after:
Module: Mathlib.CategoryTheory.Adjunction.Reflective

Goal state before:
pp: C : Type u₁
D : Type u₂
inst✝² : Category.{v₁, u₁} C
inst✝¹ : Category.{v₂, u₂} D
i : D ⥤ C
inst✝ : Reflective i
A : C
h : i.essImage A
⊢ i.essImage A

Tactic:
]

Goal state after:
C : Type u₁
D : Type u₂
inst✝² : Category.{v₁, u₁} C
inst✝¹ : Category.{v₂, u₂} D
i : D ⥤ C
inst✝ : Reflective i
A : C
h : i.essImage A
⊢ i.essImage A
Module: Mathlib.CategoryTheory.Adjunction.Reflective

Goal state before:
pp: C : Type u₁
D : Type u₂
inst✝³ : Category.{v₁, u₁} C
inst✝² : Category.{v₂, u₂} D
i : D ⥤ C
inst✝¹ : Reflective i
A : C
inst✝ : IsSplitMono ((reflectorAdjunction i).unit.app A)
η : 𝟭 C ⟶ reflector i ⋙ i := (reflectorAdjunction i).unit
this : IsIso (η.app (i.obj ((reflector i).obj A)))
⊢ Epi (η.app ((reflector i ⋙ i).obj A) ≫ (reflector i ⋙ i).map (retraction (η.app A)))

Tactic:
]

Goal state after:
C : Type u₁
D : Type u₂
inst✝³ : Category.{v₁, u₁} C
inst✝² : Category.{v₂, u₂} D
i : D ⥤ C
inst✝¹ : Reflective i
A : C
inst✝ : IsSplitMono ((reflectorAdjunction i).unit.app A)
η : 𝟭 C ⟶ reflector i ⋙ i := (reflectorAdjunction i).unit
this : IsIso (η.app (i.obj ((reflector i).obj A)))
⊢ Epi (η.app ((reflector i ⋙ i).obj A) ≫ (reflector i ⋙ i).map (retraction (η.app A)))
Module: Mathlib.Algebra.Homology.ShortComplex.Exact

Goal state before:
pp: case mp
C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Preadditive C
S : ShortComplex C
inst✝ : HasZeroObject C
hf : S.f = 0
this✝¹ : S.HasHomology
h : IsZero S.homology
this✝ : IsIso S.pOpcycles
this : Mono S.fromOpcycles
⊢ Mono (S.pOpcycles ≫ S.fromOpcycles)

Tactic:
]

Goal state after:
case mp
C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Preadditive C
S : ShortComplex C
inst✝ : HasZeroObject C
hf : S.f = 0
this✝¹ : S.HasHomology
h : IsZero S.homology
this✝ : IsIso S.pOpcycles
this : Mono S.fromOpcycles
⊢ Mono (S.pOpcycles ≫ S.fromOpcycles)
Module: Mathlib.Algebra.Homology.ShortComplex.Exact

Goal state before:
pp: case mpr
C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Preadditive C
S : ShortComplex C
inst✝ : HasZeroObject C
hf : S.f = 0
a✝ : Mono S.g
⊢ IsZero
    (HomologyData.ofIsLimitKernelFork S hf (KernelFork.ofι 0 ⋯)
          (KernelFork.IsLimit.ofMonoOfIsZero (KernelFork.ofι 0 ⋯) ⋯ ⋯)).left.H

Tactic:
]

Goal state after:
case mpr
C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Preadditive C
S : ShortComplex C
inst✝ : HasZeroObject C
hf : S.f = 0
a✝ : Mono S.g
⊢ IsZero
    (HomologyData.ofIsLimitKernelFork S hf (KernelFork.ofι 0 ⋯)
          (KernelFork.IsLimit.ofMonoOfIsZero (KernelFork.ofι 0 ⋯) ⋯ ⋯)).left.H
Module: Mathlib.CategoryTheory.Adjunction.Reflective

Goal state before:
pp: C : Type u₁
D : Type u₂
inst✝² : Category.{v₁, u₁} C
inst✝¹ : Category.{v₂, u₂} D
i : D ⥤ C
inst✝ : Reflective i
A B B' : C
h : B ⟶ B'
hB : i.essImage B
hB' : i.essImage B'
f : A ⟶ B
⊢ f ≫ h = f ≫ h

Tactic:
]

Goal state after:
Module: Mathlib.CategoryTheory.Adjunction.Reflective

Goal state before:
pp: C : Type u₁
D : Type u₂
inst✝² : Category.{v₁, u₁} C
inst✝¹ : Category.{v₂, u₂} D
j : C ⥤ D
inst✝ : Coreflective j
X : D
⊢ j.map ((coreflectorAdjunction j).unit.app ((coreflector j).obj X)) ≫
      (coreflectorAdjunction j).counit.app (j.obj ((coreflector j).obj X)) =
    j.map
      ((coreflectorAdjunction j).unit.app ((coreflector j).obj X) ≫
        (coreflector j).map ((coreflectorAdjunction j).counit.app X))

Tactic:
]

Goal state after:
C : Type u₁
D : Type u₂
inst✝² : Category.{v₁, u₁} C
inst✝¹ : Category.{v₂, u₂} D
j : C ⥤ D
inst✝ : Coreflective j
X : D
⊢ j.map ((coreflectorAdjunction j).unit.app ((coreflector j).obj X)) ≫
      (coreflectorAdjunction j).counit.app (j.obj ((coreflector j).obj X)) =
    j.map
      ((coreflectorAdjunction j).unit.app ((coreflector j).obj X) ≫
        (coreflector j).map ((coreflectorAdjunction j).counit.app X))
Module: Mathlib.CategoryTheory.Adjunction.Reflective

Goal state before:
pp: C : Type u₁
D : Type u₂
inst✝² : Category.{v₁, u₁} C
inst✝¹ : Category.{v₂, u₂} D
j : C ⥤ D
inst✝ : Coreflective j
A : D
h : j.essImage A
⊢ j.essImage A

Tactic:
]

Goal state after:
C : Type u₁
D : Type u₂
inst✝² : Category.{v₁, u₁} C
inst✝¹ : Category.{v₂, u₂} D
j : C ⥤ D
inst✝ : Coreflective j
A : D
h : j.essImage A
⊢ j.essImage A
Module: Mathlib.Algebra.Homology.ShortComplex.Exact

Goal state before:
pp: case mp
C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Preadditive C
S : ShortComplex C
inst✝ : HasZeroObject C
hg : S.g = 0
this✝¹ : S.HasHomology
h : IsZero S.homology
this✝ : IsIso S.iCycles
this : Epi S.toCycles
⊢ Epi (S.toCycles ≫ S.iCycles)

Tactic:
]

Goal state after:
case mp
C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Preadditive C
S : ShortComplex C
inst✝ : HasZeroObject C
hg : S.g = 0
this✝¹ : S.HasHomology
h : IsZero S.homology
this✝ : IsIso S.iCycles
this : Epi S.toCycles
⊢ Epi (S.toCycles ≫ S.iCycles)
Module: Mathlib.CategoryTheory.Adjunction.Reflective

Goal state before:
pp: C : Type u₁
D : Type u₂
inst✝³ : Category.{v₁, u₁} C
inst✝² : Category.{v₂, u₂} D
j : C ⥤ D
inst✝¹ : Coreflective j
A : D
inst✝ : IsSplitEpi ((coreflectorAdjunction j).counit.app A)
ε : coreflector j ⋙ j ⟶ 𝟭 D := (coreflectorAdjunction j).counit
this : IsIso (ε.app (j.obj ((coreflector j).obj A)))
⊢ Mono ((coreflector j ⋙ j).map (section_ (ε.app A)) ≫ ε.app ((coreflector j ⋙ j).obj A))

Tactic:
]

Goal state after:
C : Type u₁
D : Type u₂
inst✝³ : Category.{v₁, u₁} C
inst✝² : Category.{v₂, u₂} D
j : C ⥤ D
inst✝¹ : Coreflective j
A : D
inst✝ : IsSplitEpi ((coreflectorAdjunction j).counit.app A)
ε : coreflector j ⋙ j ⟶ 𝟭 D := (coreflectorAdjunction j).counit
this : IsIso (ε.app (j.obj ((coreflector j).obj A)))
⊢ Mono ((coreflector j ⋙ j).map (section_ (ε.app A)) ≫ ε.app ((coreflector j ⋙ j).obj A))
Module: Mathlib.Algebra.Homology.ShortComplex.Exact

Goal state before:
pp: case mpr
C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Preadditive C
S : ShortComplex C
inst✝ : HasZeroObject C
hg : S.g = 0
a✝ : Epi S.f
⊢ IsZero
    (HomologyData.ofIsColimitCokernelCofork S hg (CokernelCofork.ofπ 0 ⋯)
          (CokernelCofork.IsColimit.ofEpiOfIsZero (CokernelCofork.ofπ 0 ⋯) ⋯ ⋯)).left.H

Tactic:
]

Goal state after:
case mpr
C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Preadditive C
S : ShortComplex C
inst✝ : HasZeroObject C
hg : S.g = 0
a✝ : Epi S.f
⊢ IsZero
    (HomologyData.ofIsColimitCokernelCofork S hg (CokernelCofork.ofπ 0 ⋯)
          (CokernelCofork.IsColimit.ofEpiOfIsZero (CokernelCofork.ofπ 0 ⋯) ⋯ ⋯)).left.H
Module: Mathlib.Algebra.Homology.ShortComplex.Exact

Goal state before:
pp: case mp
C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Preadditive C
S : ShortComplex C
inst✝ : S.HasHomology
h : S.LeftHomologyData
⊢ S.Exact → Epi h.f'

Tactic:
intro hS
    exact hS.epi_f' h

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

Goal state before:
pp: C : Type u_1
inst✝³ : Category.{v_1, u_1} C
inst✝² : Preadditive C
S : ShortComplex C
inst✝¹ : S.HasHomology
inst✝ : HasKernel S.g
⊢ Epi S.toCycles ↔ Epi (kernel.lift S.g S.f ⋯)

Tactic:
]

Goal state after:
C : Type u_1
inst✝³ : Category.{v_1, u_1} C
inst✝² : Preadditive C
S : ShortComplex C
inst✝¹ : S.HasHomology
inst✝ : HasKernel S.g
⊢ Epi S.toCycles ↔ Epi (kernel.lift S.g S.f ⋯)
Module: Mathlib.Algebra.Homology.ShortComplex.Exact

Goal state before:
pp: C : Type u_1
inst✝³ : Category.{v_1, u_1} C
inst✝² : Preadditive C
S : ShortComplex C
inst✝¹ : S.HasHomology
inst✝ : HasCokernel S.f
⊢ Mono S.fromOpcycles ↔ Mono (cokernel.desc S.f S.g ⋯)

Tactic:
]

Goal state after:
C : Type u_1
inst✝³ : Category.{v_1, u_1} C
inst✝² : Preadditive C
S : ShortComplex C
inst✝¹ : S.HasHomology
inst✝ : HasCokernel S.f
⊢ Mono S.fromOpcycles ↔ Mono (cokernel.desc S.f S.g ⋯)
Module: Mathlib.Algebra.Homology.ShortComplex.Exact

Goal state before:
pp: C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Preadditive C
S : ShortComplex C
hS : IsLimit (KernelFork.ofι S.f ⋯)
inst✝ : S.HasHomology
⊢ Epi S.toCycles

Tactic:
]

Goal state after:
C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Preadditive C
S : ShortComplex C
hS : IsLimit (KernelFork.ofι S.f ⋯)
inst✝ : S.HasHomology
⊢ Epi S.toCycles
Module: Mathlib.Algebra.Homology.ShortComplex.Exact

Goal state before:
pp: C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Preadditive C
S : ShortComplex C
hS : IsLimit (KernelFork.ofι S.f ⋯)
inst✝ : S.HasHomology
⊢ hS.lift (KernelFork.ofι S.iCycles ⋯) ≫ S.f = S.iCycles

Tactic:
]

Goal state after:
C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Preadditive C
S : ShortComplex C
hS : IsLimit (KernelFork.ofι S.f ⋯)
inst✝ : S.HasHomology
⊢ hS.lift (KernelFork.ofι S.iCycles ⋯) ≫ S.f = S.iCycles
Module: Mathlib.Algebra.Homology.ShortComplex.Exact

Goal state before:
pp: C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Preadditive C
S : ShortComplex C
hS : IsLimit (KernelFork.ofι S.f ⋯)
inst✝ : S.HasHomology
⊢ S.Exact

Tactic:
rw [exact_iff_epi_toCycles]
  have : IsSplitEpi S.toCycles :=
    ⟨⟨{ section_ := hS.lift (KernelFork.ofι S.iCycles S.iCycles_g)
        id := by
          rw [← cancel_mono S.iCycles, assoc, toCycles_i, id_comp]
          exact Fork.IsLimit.lift_ι hS }⟩⟩
  infer_instance

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

Goal state before:
pp: C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Preadditive C
S : ShortComplex C
hS : IsColimit (CokernelCofork.ofπ S.g ⋯)
inst✝ : S.HasHomology
⊢ Mono S.fromOpcycles

Tactic:
]

Goal state after:
C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Preadditive C
S : ShortComplex C
hS : IsColimit (CokernelCofork.ofπ S.g ⋯)
inst✝ : S.HasHomology
⊢ Mono S.fromOpcycles
Module: Mathlib.Algebra.Homology.ShortComplex.Exact

Goal state before:
pp: C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Preadditive C
S : ShortComplex C
hS : IsColimit (CokernelCofork.ofπ S.g ⋯)
inst✝ : S.HasHomology
⊢ S.g ≫ hS.desc (CokernelCofork.ofπ S.pOpcycles ⋯) = S.pOpcycles

Tactic:
]

Goal state after:
C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Preadditive C
S : ShortComplex C
hS : IsColimit (CokernelCofork.ofπ S.g ⋯)
inst✝ : S.HasHomology
⊢ S.g ≫ hS.desc (CokernelCofork.ofπ S.pOpcycles ⋯) = S.pOpcycles
Module: Mathlib.Algebra.Homology.ShortComplex.Exact

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : Preadditive C
S : ShortComplex C
hS : S.Exact
hf : S.f = 0
this✝ : S.HasHomology
this : Epi S.toCycles
⊢ 0 = 0

Tactic:
]

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

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : Preadditive C
S : ShortComplex C
hS : S.Exact
hf : S.f = 0
this✝¹ : S.HasHomology
this✝ : Epi S.toCycles
this : S.iCycles = 0
A : C
x₂ : A ⟶ S.X₂
hx₂ : x₂ ≫ S.g = 0
⊢ 0 = 0

Tactic:
]

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

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : Preadditive C
S : ShortComplex C
hS : S.Exact
hf : S.f = 0
⊢ Mono S.g

Tactic:
by
  have := hS.hasHomology
  have := hS.epi_toCycles
  have : S.iCycles = 0 := by rw [← cancel_epi S.toCycles, comp_zero, toCycles_i, hf]
  apply Preadditive.mono_of_cancel_zero
  intro A x₂ hx₂
  rw [← S.liftCycles_i x₂ hx₂, this, comp_zero]

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

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : Preadditive C
S : ShortComplex C
hS : S.Exact
hg : S.g = 0
this✝ : S.HasHomology
this : Mono S.fromOpcycles
⊢ 0 = 0

Tactic:
]

Goal state after:
Module: Mathlib.CategoryTheory.Subobject.FactorThru

Goal state before:
pp: C : Type u₁
inst✝¹ : Category.{v₁, u₁} C
X✝ Y✝ Z : C
D : Type u₂
inst✝ : Category.{v₂, u₂} D
X Y : C
P✝ : Subobject Y
f : X ⟶ Y
P Q : MonoOver Y
h : P ≅ Q
i : X ⟶ P.obj.left
w : i ≫ P.arrow = f
⊢ f = f

Tactic:
]

Goal state after:
Module: Mathlib.CategoryTheory.Subobject.FactorThru

Goal state before:
pp: C : Type u₁
inst✝¹ : Category.{v₁, u₁} C
X✝ Y✝ Z : C
D : Type u₂
inst✝ : Category.{v₂, u₂} D
X Y : C
P✝ : Subobject Y
f : X ⟶ Y
P Q : MonoOver Y
h : P ≅ Q
i : X ⟶ Q.obj.left
w : i ≫ Q.arrow = f
⊢ f = f

Tactic:
]

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

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : Preadditive C
S : ShortComplex C
hS : S.Exact
hg : S.g = 0
this✝¹ : S.HasHomology
this✝ : Mono S.fromOpcycles
this : S.pOpcycles = 0
A : C
x₂ : S.X₂ ⟶ A
hx₂ : S.f ≫ x₂ = 0
⊢ 0 = 0

Tactic:
]

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

Goal state before:
pp: case mp
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : Preadditive C
S : ShortComplex C
hS : S.Exact
a✝ : Mono S.g
⊢ 0 = 0

Tactic:
]

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

Goal state before:
pp: case mp
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : Preadditive C
S : ShortComplex C
hS : S.Exact
a✝ : Epi S.f
⊢ 0 = 0

Tactic:
]

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

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : Preadditive C
S : ShortComplex C
hS : S.Exact
hf : S.f = 0
hg : S.g = 0
this : Mono S.g
⊢ 0 = 0

Tactic:
]

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

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : Preadditive C
S : ShortComplex C
s : S.Splitting
⊢ s.r ≫ S.f = s.r ≫ S.f

Tactic:
]

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

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : Preadditive C
S : ShortComplex C
s : S.Splitting
⊢ S.g ≫ s.s = S.g ≫ s.s

Tactic:
]

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

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : Preadditive C
S : ShortComplex C
s s' : S.Splitting
h : s.r = s'.r
this : Epi S.g
eq : s.s = s'.s
⊢ s = s'

Tactic:
]

Goal state after:
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : Preadditive C
S : ShortComplex C
s s' : S.Splitting
h : s.r = s'.r
this : Epi S.g
eq : s.s = s'.s
⊢ s = s'
Module: Mathlib.Algebra.Homology.ShortComplex.Exact

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : Preadditive C
S : ShortComplex C
s s' : S.Splitting
h : s.s = s'.s
this : Mono S.f
eq : s.r = s'.r
⊢ s = s'

Tactic:
]

Goal state after:
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : Preadditive C
S : ShortComplex C
s s' : S.Splitting
h : s.s = s'.s
this : Mono S.f
eq : s.r = s'.r
⊢ s = s'
Module: Mathlib.Algebra.Homology.ShortComplex.Exact

Goal state before:
pp: C : Type u_1
D : Type u_2
inst✝⁴ : Category.{v_1, u_1} C
inst✝³ : Category.{v_2, u_2} D
inst✝² : Preadditive C
inst✝¹ : Preadditive D
S : ShortComplex C
inst✝ : HasZeroObject C
s : S.Splitting
hi : IsLimit (KernelFork.ofι S.f ⋯)
f' : (KernelFork.ofι S.f ⋯).pt ⟶ (KernelFork.ofι S.f ⋯).pt := hi.lift (KernelFork.ofι S.f ⋯)
hf' : f' = 𝟙 (KernelFork.ofι S.f ⋯).pt
wπ : f' ≫ 0 = 0
⊢ Epi (𝟙 (KernelFork.ofι S.f ⋯).pt)

Tactic:
]

Goal state after:
C : Type u_1
D : Type u_2
inst✝⁴ : Category.{v_1, u_1} C
inst✝³ : Category.{v_2, u_2} D
inst✝² : Preadditive C
inst✝¹ : Preadditive D
S : ShortComplex C
inst✝ : HasZeroObject C
s : S.Splitting
hi : IsLimit (KernelFork.ofι S.f ⋯)
f' : (KernelFork.ofι S.f ⋯).pt ⟶ (KernelFork.ofι S.f ⋯).pt := hi.lift (KernelFork.ofι S.f ⋯)
hf' : f' = 𝟙 (KernelFork.ofι S.f ⋯).pt
wπ : f' ≫ 0 = 0
⊢ Epi (𝟙 (KernelFork.ofι S.f ⋯).pt)
Module: Mathlib.Algebra.Homology.ShortComplex.Exact

Goal state before:
pp: C : Type u_1
D : Type u_2
inst✝⁴ : Category.{v_1, u_1} C
inst✝³ : Category.{v_2, u_2} D
inst✝² : Preadditive C
inst✝¹ : Preadditive D
S : ShortComplex C
inst✝ : HasZeroObject C
s : S.Splitting
hp : IsColimit (CokernelCofork.ofπ S.g ⋯)
g' : (CokernelCofork.ofπ S.g ⋯).pt ⟶ (CokernelCofork.ofπ S.g ⋯).pt := hp.desc (CokernelCofork.ofπ S.g ⋯)
hg' : g' = 𝟙 (CokernelCofork.ofπ S.g ⋯).pt
wι : 0 ≫ g' = 0
⊢ Mono (𝟙 (CokernelCofork.ofπ S.g ⋯).pt)

Tactic:
]

Goal state after:
C : Type u_1
D : Type u_2
inst✝⁴ : Category.{v_1, u_1} C
inst✝³ : Category.{v_2, u_2} D
inst✝² : Preadditive C
inst✝¹ : Preadditive D
S : ShortComplex C
inst✝ : HasZeroObject C
s : S.Splitting
hp : IsColimit (CokernelCofork.ofπ S.g ⋯)
g' : (CokernelCofork.ofπ S.g ⋯).pt ⟶ (CokernelCofork.ofπ S.g ⋯).pt := hp.desc (CokernelCofork.ofπ S.g ⋯)
hg' : g' = 𝟙 (CokernelCofork.ofπ S.g ⋯).pt
wι : 0 ≫ g' = 0
⊢ Mono (𝟙 (CokernelCofork.ofπ S.g ⋯).pt)
Module: Mathlib.Algebra.Homology.ShortComplex.Exact

Goal state before:
pp: C : Type u_1
D : Type u_2
inst✝⁴ : Category.{v_1, u_1} C
inst✝³ : Category.{v_2, u_2} D
inst✝² : Preadditive C
inst✝¹ : Preadditive D
S : ShortComplex C
s : S.Splitting
F : C ⥤ D
inst✝ : F.Additive
⊢ 𝟙 (F.obj S.X₁) = 𝟙 (F.obj S.X₁)

Tactic:
]

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

Goal state before:
pp: C : Type u_1
D : Type u_2
inst✝³ : Category.{v_1, u_1} C
inst✝² : Category.{v_2, u_2} D
inst✝¹ : Preadditive C
inst✝ : Preadditive D
S S₁ S₂ : ShortComplex C
s : S₁.Splitting
e : S₁ ≅ S₂
⊢ 𝟙 S₂.X₁ = 𝟙 S₂.X₁

Tactic:
]

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

Goal state before:
pp: C : Type u_1
D : Type u_2
inst✝³ : Category.{v_1, u_1} C
inst✝² : Category.{v_2, u_2} D
inst✝¹ : Preadditive C
inst✝ : Preadditive D
S S₁ S₂ : ShortComplex C
s : S₁.Splitting
e : S₁ ≅ S₂
⊢ 𝟙 S₂.X₃ = 𝟙 S₂.X₃

Tactic:
]

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

Goal state before:
pp: C : Type u_1
D : Type u_2
inst✝³ : Category.{v_1, u_1} C
inst✝² : Category.{v_2, u_2} D
inst✝¹ : Preadditive C
inst✝ : Preadditive D
S S₁ S₂ : ShortComplex C
s : S₁.Splitting
e : S₁ ≅ S₂
eq : e.inv.τ₂ ≫ (s.r ≫ S₁.f + S₁.g ≫ s.s) ≫ e.hom.τ₂ = 𝟙 S₂.X₂
⊢ (e.inv.τ₂ ≫ s.r ≫ e.hom.τ₁) ≫ S₂.f + S₂.g ≫ e.inv.τ₃ ≫ s.s ≫ e.hom.τ₂ = 𝟙 S₂.X₂

Tactic:
]

Goal state after:
C : Type u_1
D : Type u_2
inst✝³ : Category.{v_1, u_1} C
inst✝² : Category.{v_2, u_2} D
inst✝¹ : Preadditive C
inst✝ : Preadditive D
S S₁ S₂ : ShortComplex C
s : S₁.Splitting
e : S₁ ≅ S₂
eq : e.inv.τ₂ ≫ (s.r ≫ S₁.f + S₁.g ≫ s.s) ≫ e.hom.τ₂ = 𝟙 S₂.X₂
⊢ (e.inv.τ₂ ≫ s.r ≫ e.hom.τ₁) ≫ S₂.f + S₂.g ≫ e.inv.τ₃ ≫ s.s ≫ e.hom.τ₂ = 𝟙 S₂.X₂
Module: Mathlib.Algebra.Homology.ShortComplex.Exact

Goal state before:
pp: C : Type u_1
D : Type u_2
inst✝³ : Category.{v_1, u_1} C
inst✝² : Category.{v_2, u_2} D
inst✝¹ : Preadditive C
inst✝ : Preadditive D
S S₁ S₂ : ShortComplex C
s : S₁.Splitting
e : S₁ ≅ S₂
eq : e.inv.τ₂ ≫ (s.r ≫ S₁.f + S₁.g ≫ s.s) ≫ e.hom.τ₂ = 𝟙 S₂.X₂
⊢ e.inv.τ₂ ≫ s.r ≫ S₁.f ≫ e.hom.τ₂ + S₂.g ≫ e.inv.τ₃ ≫ s.s ≫ e.hom.τ₂ =
    e.inv.τ₂ ≫ s.r ≫ S₁.f ≫ e.hom.τ₂ + S₂.g ≫ e.inv.τ₃ ≫ s.s ≫ e.hom.τ₂

Tactic:
]

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

Goal state before:
pp: C : Type u₁
inst✝¹ : Category.{v₁, u₁} C
B A : C
X : Subobject B
f : A ⟶ B
inst✝ : Mono f
i : A ≅ underlying.obj X
w : i.hom ≫ X.arrow = f
⊢ f = f

Tactic:
]

Goal state after:
Module: Mathlib.CategoryTheory.Subobject.MonoOver

Goal state before:
pp: C : Type u₁
inst✝¹ : Category.{v₁, u₁} C
X✝ Y Z : C
D : Type u₂
inst✝ : Category.{v₂, u₂} D
X : C
f g : MonoOver X
h₁ h₂ : f ⟶ g
⊢ f.obj.hom = f.obj.hom

Tactic:
]

Goal state after: