Module: Mathlib.Analysis.Normed.Operator.Fredholm.Basic

Goal state before:
pp: case refine_1
𝕜 : Type u_1
E : Type u_2
F : Type u_3
inst✝¹¹ : NontriviallyNormedField 𝕜
inst✝¹⁰ : AddCommGroup E
inst✝⁹ : AddCommGroup F
inst✝⁸ : Module 𝕜 E
inst✝⁷ : Module 𝕜 F
inst✝⁶ : TopologicalSpace E
inst✝⁵ : TopologicalSpace F
inst✝⁴ : CompleteSpace 𝕜
inst✝³ : IsTopologicalAddGroup E
inst✝² : ContinuousSMul 𝕜 E
inst✝¹ : IsTopologicalAddGroup F
inst✝ : ContinuousSMul 𝕜 F
u : E →L[𝕜] F
E₁ : Submodule 𝕜 E
E₁_closed : IsClosed[inst✝⁶] ↑E₁
E₁_coFG : E₁.CoFG
F₁ : Submodule 𝕜 F
F₁_closed : IsClosed[inst✝⁵] ↑F₁
F₁_coFG : F₁.CoFG
h_mapsto : MapsTo ⇑u ↑E₁ ↑F₁
e : ↥E₁ ≃L[𝕜] ↥F₁
he : ↑e = u.restrict h_mapsto
eqL : u.domRestrict E₁ = F₁.subtypeL ∘SL ↑e
eqₗ : (↑u).domRestrict E₁ = F₁.subtype ∘ₗ ↑↑e
h : IsStrictMap ⇑u ∧ IsClosed[inst✝⁵] ↑(↑u).range
disj : Disjoint E₁ (↑u).ker
⊢ FiniteDimensional 𝕜 ↥(↑u).ker

pp: case refine_2
𝕜 : Type u_1
E : Type u_2
F : Type u_3
inst✝¹¹ : NontriviallyNormedField 𝕜
inst✝¹⁰ : AddCommGroup E
inst✝⁹ : AddCommGroup F
inst✝⁸ : Module 𝕜 E
inst✝⁷ : Module 𝕜 F
inst✝⁶ : TopologicalSpace E
inst✝⁵ : TopologicalSpace F
inst✝⁴ : CompleteSpace 𝕜
inst✝³ : IsTopologicalAddGroup E
inst✝² : ContinuousSMul 𝕜 E
inst✝¹ : IsTopologicalAddGroup F
inst✝ : ContinuousSMul 𝕜 F
u : E →L[𝕜] F
E₁ : Submodule 𝕜 E
E₁_closed : IsClosed[inst✝⁶] ↑E₁
E₁_coFG : E₁.CoFG
F₁ : Submodule 𝕜 F
F₁_closed : IsClosed[inst✝⁵] ↑F₁
F₁_coFG : F₁.CoFG
h_mapsto : MapsTo ⇑u ↑E₁ ↑F₁
e : ↥E₁ ≃L[𝕜] ↥F₁
he : ↑e = u.restrict h_mapsto
eqL : u.domRestrict E₁ = F₁.subtypeL ∘SL ↑e
eqₗ : (↑u).domRestrict E₁ = F₁.subtype ∘ₗ ↑↑e
h : IsStrictMap ⇑u ∧ IsClosed[inst✝⁵] ↑(↑u).range
disj : Disjoint E₁ (↑u).ker
⊢ (↑u).range.CoFG

pp: case refine_3
𝕜 : Type u_1
E : Type u_2
F : Type u_3
inst✝¹¹ : NontriviallyNormedField 𝕜
inst✝¹⁰ : AddCommGroup E
inst✝⁹ : AddCommGroup F
inst✝⁸ : Module 𝕜 E
inst✝⁷ : Module 𝕜 F
inst✝⁶ : TopologicalSpace E
inst✝⁵ : TopologicalSpace F
inst✝⁴ : CompleteSpace 𝕜
inst✝³ : IsTopologicalAddGroup E
inst✝² : ContinuousSMul 𝕜 E
inst✝¹ : IsTopologicalAddGroup F
inst✝ : ContinuousSMul 𝕜 F
u : E →L[𝕜] F
E₁ : Submodule 𝕜 E
E₁_closed : IsClosed[inst✝⁶] ↑E₁
E₁_coFG : E₁.CoFG
F₁ : Submodule 𝕜 F
F₁_closed : IsClosed[inst✝⁵] ↑F₁
F₁_coFG : F₁.CoFG
h_mapsto : MapsTo ⇑u ↑E₁ ↑F₁
e : ↥E₁ ≃L[𝕜] ↥F₁
he : ↑e = u.restrict h_mapsto
eqL : u.domRestrict E₁ = F₁.subtypeL ∘SL ↑e
eqₗ : (↑u).domRestrict E₁ = F₁.subtype ∘ₗ ↑↑e
h : IsStrictMap ⇑u ∧ IsClosed[inst✝⁵] ↑(↑u).range
disj : Disjoint E₁ (↑u).ker
⊢ (↑u).ker.ClosedComplemented

Tactic:
· rw [← Submodule.fg_iff_finiteDimensional]
    exact E₁_coFG.fg_of_disjoint disj.symm

Goal state after:
case refine_2
𝕜 : Type u_1
E : Type u_2
F : Type u_3
inst✝¹¹ : NontriviallyNormedField 𝕜
inst✝¹⁰ : AddCommGroup E
inst✝⁹ : AddCommGroup F
inst✝⁸ : Module 𝕜 E
inst✝⁷ : Module 𝕜 F
inst✝⁶ : TopologicalSpace E
inst✝⁵ : TopologicalSpace F
inst✝⁴ : CompleteSpace 𝕜
inst✝³ : IsTopologicalAddGroup E
inst✝² : ContinuousSMul 𝕜 E
inst✝¹ : IsTopologicalAddGroup F
inst✝ : ContinuousSMul 𝕜 F
u : E →L[𝕜] F
E₁ : Submodule 𝕜 E
E₁_closed : IsClosed[inst✝⁶] ↑E₁
E₁_coFG : E₁.CoFG
F₁ : Submodule 𝕜 F
F₁_closed : IsClosed[inst✝⁵] ↑F₁
F₁_coFG : F₁.CoFG
h_mapsto : MapsTo ⇑u ↑E₁ ↑F₁
e : ↥E₁ ≃L[𝕜] ↥F₁
he : ↑e = u.restrict h_mapsto
eqL : u.domRestrict E₁ = F₁.subtypeL ∘SL ↑e
eqₗ : (↑u).domRestrict E₁ = F₁.subtype ∘ₗ ↑↑e
h : IsStrictMap ⇑u ∧ IsClosed[inst✝⁵] ↑(↑u).range
disj : Disjoint E₁ (↑u).ker
⊢ (↑u).range.CoFG

case refine_3
𝕜 : Type u_1
E : Type u_2
F : Type u_3
inst✝¹¹ : NontriviallyNormedField 𝕜
inst✝¹⁰ : AddCommGroup E
inst✝⁹ : AddCommGroup F
inst✝⁸ : Module 𝕜 E
inst✝⁷ : Module 𝕜 F
inst✝⁶ : TopologicalSpace E
inst✝⁵ : TopologicalSpace F
inst✝⁴ : CompleteSpace 𝕜
inst✝³ : IsTopologicalAddGroup E
inst✝² : ContinuousSMul 𝕜 E
inst✝¹ : IsTopologicalAddGroup F
inst✝ : ContinuousSMul 𝕜 F
u : E →L[𝕜] F
E₁ : Submodule 𝕜 E
E₁_closed : IsClosed[inst✝⁶] ↑E₁
E₁_coFG : E₁.CoFG
F₁ : Submodule 𝕜 F
F₁_closed : IsClosed[inst✝⁵] ↑F₁
F₁_coFG : F₁.CoFG
h_mapsto : MapsTo ⇑u ↑E₁ ↑F₁
e : ↥E₁ ≃L[𝕜] ↥F₁
he : ↑e = u.restrict h_mapsto
eqL : u.domRestrict E₁ = F₁.subtypeL ∘SL ↑e
eqₗ : (↑u).domRestrict E₁ = F₁.subtype ∘ₗ ↑↑e
h : IsStrictMap ⇑u ∧ IsClosed[inst✝⁵] ↑(↑u).range
disj : Disjoint E₁ (↑u).ker
⊢ (↑u).ker.ClosedComplemented