Theorem: TopCat.Presheaf.isIso_of_stalkFunctor_map_iso
File: Mathlib/Topology/Sheaves/Stalks.lean

tactic: suffices IsIso ((Sheaf.forget C X).map f) by exact isIso_of_fully_faithful (Sheaf.forget C X) f
state_before: C : Type u
inst✝⁷ : Category C
inst✝⁶ : HasColimits C
X Y Z : TopCat
inst✝⁵ : ConcreteCategory C
inst✝⁴ : PreservesFilteredColimits (forget C)
inst✝³ : HasLimits C
inst✝² : PreservesLimits (forget C)
inst✝¹ : ReflectsIsomorphisms (forget C)
F G : Sheaf C X
f : F ⟶ G
inst✝ : ∀ (x : ↑X), IsIso ((stalkFunctor C x).map f.val)
⊢ IsIso f

tactic: suffices ∀ U : (Opens X)ᵒᵖ, IsIso (f.1.app U) by
  exact @NatIso.isIso_of_isIso_app _ _ _ _ F.1 G.1 f.1 this
state_before: C : Type u
inst✝⁷ : Category C
inst✝⁶ : HasColimits C
X Y Z : TopCat
inst✝⁵ : ConcreteCategory C
inst✝⁴ : PreservesFilteredColimits (forget C)
inst✝³ : HasLimits C
inst✝² : PreservesLimits (forget C)
inst✝¹ : ReflectsIsomorphisms (forget C)
F G : Sheaf C X
f : F ⟶ G
inst✝ : ∀ (x : ↑X), IsIso ((stalkFunctor C x).map f.val)
⊢ IsIso ((Sheaf.forget C X).map f)

tactic: intro U
state_before: C : Type u
inst✝⁷ : Category C
inst✝⁶ : HasColimits C
X Y Z : TopCat
inst✝⁵ : ConcreteCategory C
inst✝⁴ : PreservesFilteredColimits (forget C)
inst✝³ : HasLimits C
inst✝² : PreservesLimits (forget C)
inst✝¹ : ReflectsIsomorphisms (forget C)
F G : Sheaf C X
f : F ⟶ G
inst✝ : ∀ (x : ↑X), IsIso ((stalkFunctor C x).map f.val)
⊢ ∀ (U : (Opens ↑X)ᵒᵖ), IsIso (f.val.app U)

tactic: induction U
state_before: C : Type u
inst✝⁷ : Category C
inst✝⁶ : HasColimits C
X Y Z : TopCat
inst✝⁵ : ConcreteCategory C
inst✝⁴ : PreservesFilteredColimits (forget C)
inst✝³ : HasLimits C
inst✝² : PreservesLimits (forget C)
inst✝¹ : ReflectsIsomorphisms (forget C)
F G : Sheaf C X
f : F ⟶ G
inst✝ : ∀ (x : ↑X), IsIso ((stalkFunctor C x).map f.val)
U : (Opens ↑X)ᵒᵖ
⊢ IsIso (f.val.app U)

tactic: apply app_isIso_of_stalkFunctor_map_iso
state_before: case h
C : Type u
inst✝⁷ : Category C
inst✝⁶ : HasColimits C
X Y Z : TopCat
inst✝⁵ : ConcreteCategory C
inst✝⁴ : PreservesFilteredColimits (forget C)
inst✝³ : HasLimits C
inst✝² : PreservesLimits (forget C)
inst✝¹ : ReflectsIsomorphisms (forget C)
F G : Sheaf C X
f : F ⟶ G
inst✝ : ∀ (x : ↑X), IsIso ((stalkFunctor C x).map f.val)
X✝ : Opens ↑X
⊢ IsIso (f.val.app X✝.op)

tactic: exact isIso_of_fully_faithful (Sheaf.forget C X) f
state_before: C : Type u
inst✝⁷ : Category C
inst✝⁶ : HasColimits C
X Y Z : TopCat
inst✝⁵ : ConcreteCategory C
inst✝⁴ : PreservesFilteredColimits (forget C)
inst✝³ : HasLimits C
inst✝² : PreservesLimits (forget C)
inst✝¹ : ReflectsIsomorphisms (forget C)
F G : Sheaf C X
f : F ⟶ G
inst✝ : ∀ (x : ↑X), IsIso ((stalkFunctor C x).map f.val)
this : IsIso ((Sheaf.forget C X).map f)
⊢ IsIso f

tactic: exact @NatIso.isIso_of_isIso_app _ _ _ _ F.1 G.1 f.1 this
state_before: C : Type u
inst✝⁷ : Category C
inst✝⁶ : HasColimits C
X Y Z : TopCat
inst✝⁵ : ConcreteCategory C
inst✝⁴ : PreservesFilteredColimits (forget C)
inst✝³ : HasLimits C
inst✝² : PreservesLimits (forget C)
inst✝¹ : ReflectsIsomorphisms (forget C)
F G : Sheaf C X
f : F ⟶ G
inst✝ : ∀ (x : ↑X), IsIso ((stalkFunctor C x).map f.val)
this : ∀ (U : (Opens ↑X)ᵒᵖ), IsIso (f.val.app U)
⊢ IsIso ((Sheaf.forget C X).map f)