Theorem: Zspan.fundamentalDomain_ae_parallelepiped
File: Mathlib/Algebra/Module/Zlattice/Basic.lean

tactic: classical
have : FiniteDimensional ℝ E := FiniteDimensional.of_fintype_basis b
rw [← measure_symmDiff_eq_zero_iff, symmDiff_of_le (fundamentalDomain_subset_parallelepiped b)]
suffices (parallelepiped b \ fundamentalDomain b) ⊆ ⋃ i,
    AffineSubspace.mk' (b i) (span ℝ (b '' (Set.univ \ {i}))) by
  refine measure_mono_null this
    (measure_iUnion_null_iff.mpr fun i ↦ Measure.addHaar_affineSubspace μ _ ?_)
  refine (ne_of_mem_of_not_mem' (AffineSubspace.mem_top _ _ 0)
    (AffineSubspace.mem_mk'_iff_vsub_mem.not.mpr ?_)).symm
  simp_rw [vsub_eq_sub, zero_sub, neg_mem_iff]
  exact linearIndependent_iff_not_mem_span.mp b.linearIndependent i
intro x hx
simp_rw [parallelepiped_basis_eq, Set.mem_Icc, Set.mem_diff, Set.mem_setOf_eq,
  mem_fundamentalDomain, Set.mem_Ico, not_forall, not_and, not_lt] at hx
obtain ⟨i, hi⟩ := hx.2
have : b.repr x i = 1 := le_antisymm (hx.1 i).2 (hi (hx.1 i).1)
rw [← b.sum_repr x, ← Finset.sum_erase_add _ _ (Finset.mem_univ i), this, one_smul, ← vadd_eq_add]
refine Set.mem_iUnion.mpr ⟨i, AffineSubspace.vadd_mem_mk' _
  (sum_smul_mem _ _ (fun i hi ↦ Submodule.subset_span ?_))⟩
exact ⟨i, Set.mem_diff_singleton.mpr ⟨trivial, Finset.ne_of_mem_erase hi⟩, rfl⟩
state_before: E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
⊢ fundamentalDomain b =ᶠ[ae μ] parallelepiped ⇑b
state_after: no goals

tactic: have : FiniteDimensional ℝ E := FiniteDimensional.of_fintype_basis b
state_before: E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
⊢ fundamentalDomain b =ᶠ[ae μ] parallelepiped ⇑b
state_after: E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this : FiniteDimensional ℝ E
⊢ fundamentalDomain b =ᶠ[ae μ] parallelepiped ⇑b

tactic: rw [← measure_symmDiff_eq_zero_iff, symmDiff_of_le (fundamentalDomain_subset_parallelepiped b)]
state_before: E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this : FiniteDimensional ℝ E
⊢ fundamentalDomain b =ᶠ[ae μ] parallelepiped ⇑b
state_after: E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this : FiniteDimensional ℝ E
⊢ μ (parallelepiped ⇑b \ fundamentalDomain b) = 0

tactic: suffices (parallelepiped b \ fundamentalDomain b) ⊆ ⋃ i,
    AffineSubspace.mk' (b i) (span ℝ (b '' (Set.univ \ {i}))) by
  refine measure_mono_null this
    (measure_iUnion_null_iff.mpr fun i ↦ Measure.addHaar_affineSubspace μ _ ?_)
  refine (ne_of_mem_of_not_mem' (AffineSubspace.mem_top _ _ 0)
    (AffineSubspace.mem_mk'_iff_vsub_mem.not.mpr ?_)).symm
  simp_rw [vsub_eq_sub, zero_sub, neg_mem_iff]
  exact linearIndependent_iff_not_mem_span.mp b.linearIndependent i
state_before: E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this : FiniteDimensional ℝ E
⊢ μ (parallelepiped ⇑b \ fundamentalDomain b) = 0
state_after: E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this : FiniteDimensional ℝ E
⊢ parallelepiped ⇑b \ fundamentalDomain b ⊆ ⋃ i, ↑(AffineSubspace.mk' (b i) (span ℝ (⇑b '' (Set.univ \ {i}))))

tactic: intro x hx
state_before: E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this : FiniteDimensional ℝ E
⊢ parallelepiped ⇑b \ fundamentalDomain b ⊆ ⋃ i, ↑(AffineSubspace.mk' (b i) (span ℝ (⇑b '' (Set.univ \ {i}))))
state_after: E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this : FiniteDimensional ℝ E
x : E
hx : x ∈ parallelepiped ⇑b \ fundamentalDomain b
⊢ x ∈ ⋃ i, ↑(AffineSubspace.mk' (b i) (span ℝ (⇑b '' (Set.univ \ {i}))))

tactic: simp_rw [parallelepiped_basis_eq, Set.mem_Icc, Set.mem_diff, Set.mem_setOf_eq,
  mem_fundamentalDomain, Set.mem_Ico, not_forall, not_and, not_lt] at hx
state_before: E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this : FiniteDimensional ℝ E
x : E
hx : x ∈ parallelepiped ⇑b \ fundamentalDomain b
⊢ x ∈ ⋃ i, ↑(AffineSubspace.mk' (b i) (span ℝ (⇑b '' (Set.univ \ {i}))))
state_after: E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this : FiniteDimensional ℝ E
x : E
hx : (∀ (i : ι), 0 ≤ (b.repr x) i ∧ (b.repr x) i ≤ 1) ∧ ∃ x_1, 0 ≤ (b.repr x) x_1 → 1 ≤ (b.repr x) x_1
⊢ x ∈ ⋃ i, ↑(AffineSubspace.mk' (b i) (span ℝ (⇑b '' (Set.univ \ {i}))))

tactic: obtain ⟨i, hi⟩ := hx.2
state_before: E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this : FiniteDimensional ℝ E
x : E
hx : (∀ (i : ι), 0 ≤ (b.repr x) i ∧ (b.repr x) i ≤ 1) ∧ ∃ x_1, 0 ≤ (b.repr x) x_1 → 1 ≤ (b.repr x) x_1
⊢ x ∈ ⋃ i, ↑(AffineSubspace.mk' (b i) (span ℝ (⇑b '' (Set.univ \ {i}))))
state_after: case intro
E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this : FiniteDimensional ℝ E
x : E
hx : (∀ (i : ι), 0 ≤ (b.repr x) i ∧ (b.repr x) i ≤ 1) ∧ ∃ x_1, 0 ≤ (b.repr x) x_1 → 1 ≤ (b.repr x) x_1
i : ι
hi : 0 ≤ (b.repr x) i → 1 ≤ (b.repr x) i
⊢ x ∈ ⋃ i, ↑(AffineSubspace.mk' (b i) (span ℝ (⇑b '' (Set.univ \ {i}))))

tactic: have : b.repr x i = 1 := le_antisymm (hx.1 i).2 (hi (hx.1 i).1)
state_before: case intro
E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this : FiniteDimensional ℝ E
x : E
hx : (∀ (i : ι), 0 ≤ (b.repr x) i ∧ (b.repr x) i ≤ 1) ∧ ∃ x_1, 0 ≤ (b.repr x) x_1 → 1 ≤ (b.repr x) x_1
i : ι
hi : 0 ≤ (b.repr x) i → 1 ≤ (b.repr x) i
⊢ x ∈ ⋃ i, ↑(AffineSubspace.mk' (b i) (span ℝ (⇑b '' (Set.univ \ {i}))))
state_after: case intro
E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this✝ : FiniteDimensional ℝ E
x : E
hx : (∀ (i : ι), 0 ≤ (b.repr x) i ∧ (b.repr x) i ≤ 1) ∧ ∃ x_1, 0 ≤ (b.repr x) x_1 → 1 ≤ (b.repr x) x_1
i : ι
hi : 0 ≤ (b.repr x) i → 1 ≤ (b.repr x) i
this : (b.repr x) i = 1
⊢ x ∈ ⋃ i, ↑(AffineSubspace.mk' (b i) (span ℝ (⇑b '' (Set.univ \ {i}))))

tactic: rw [← b.sum_repr x, ← Finset.sum_erase_add _ _ (Finset.mem_univ i), this, one_smul, ← vadd_eq_add]
state_before: case intro
E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this✝ : FiniteDimensional ℝ E
x : E
hx : (∀ (i : ι), 0 ≤ (b.repr x) i ∧ (b.repr x) i ≤ 1) ∧ ∃ x_1, 0 ≤ (b.repr x) x_1 → 1 ≤ (b.repr x) x_1
i : ι
hi : 0 ≤ (b.repr x) i → 1 ≤ (b.repr x) i
this : (b.repr x) i = 1
⊢ x ∈ ⋃ i, ↑(AffineSubspace.mk' (b i) (span ℝ (⇑b '' (Set.univ \ {i}))))
state_after: case intro
E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this✝ : FiniteDimensional ℝ E
x : E
hx : (∀ (i : ι), 0 ≤ (b.repr x) i ∧ (b.repr x) i ≤ 1) ∧ ∃ x_1, 0 ≤ (b.repr x) x_1 → 1 ≤ (b.repr x) x_1
i : ι
hi : 0 ≤ (b.repr x) i → 1 ≤ (b.repr x) i
this : (b.repr x) i = 1
⊢ ∑ x_1 ∈ Finset.univ.erase i, (b.repr x) x_1 • b x_1 +ᵥ b i ∈
    ⋃ i, ↑(AffineSubspace.mk' (b i) (span ℝ (⇑b '' (Set.univ \ {i}))))

tactic: refine Set.mem_iUnion.mpr ⟨i, AffineSubspace.vadd_mem_mk' _
  (sum_smul_mem _ _ (fun i hi ↦ Submodule.subset_span ?_))⟩
state_before: case intro
E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this✝ : FiniteDimensional ℝ E
x : E
hx : (∀ (i : ι), 0 ≤ (b.repr x) i ∧ (b.repr x) i ≤ 1) ∧ ∃ x_1, 0 ≤ (b.repr x) x_1 → 1 ≤ (b.repr x) x_1
i : ι
hi : 0 ≤ (b.repr x) i → 1 ≤ (b.repr x) i
this : (b.repr x) i = 1
⊢ ∑ x_1 ∈ Finset.univ.erase i, (b.repr x) x_1 • b x_1 +ᵥ b i ∈
    ⋃ i, ↑(AffineSubspace.mk' (b i) (span ℝ (⇑b '' (Set.univ \ {i}))))
state_after: case intro
E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this✝ : FiniteDimensional ℝ E
x : E
hx : (∀ (i : ι), 0 ≤ (b.repr x) i ∧ (b.repr x) i ≤ 1) ∧ ∃ x_1, 0 ≤ (b.repr x) x_1 → 1 ≤ (b.repr x) x_1
i✝ : ι
hi✝ : 0 ≤ (b.repr x) i✝ → 1 ≤ (b.repr x) i✝
this : (b.repr x) i✝ = 1
i : ι
hi : i ∈ Finset.univ.erase i✝
⊢ b i ∈ ⇑b '' (Set.univ \ {i✝})

tactic: exact ⟨i, Set.mem_diff_singleton.mpr ⟨trivial, Finset.ne_of_mem_erase hi⟩, rfl⟩
state_before: case intro
E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this✝ : FiniteDimensional ℝ E
x : E
hx : (∀ (i : ι), 0 ≤ (b.repr x) i ∧ (b.repr x) i ≤ 1) ∧ ∃ x_1, 0 ≤ (b.repr x) x_1 → 1 ≤ (b.repr x) x_1
i✝ : ι
hi✝ : 0 ≤ (b.repr x) i✝ → 1 ≤ (b.repr x) i✝
this : (b.repr x) i✝ = 1
i : ι
hi : i ∈ Finset.univ.erase i✝
⊢ b i ∈ ⇑b '' (Set.univ \ {i✝})
state_after: no goals

tactic: refine measure_mono_null this
  (measure_iUnion_null_iff.mpr fun i ↦ Measure.addHaar_affineSubspace μ _ ?_)
state_before: E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this✝ : FiniteDimensional ℝ E
this : parallelepiped ⇑b \ fundamentalDomain b ⊆ ⋃ i, ↑(AffineSubspace.mk' (b i) (span ℝ (⇑b '' (Set.univ \ {i}))))
⊢ μ (parallelepiped ⇑b \ fundamentalDomain b) = 0
state_after: E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this✝ : FiniteDimensional ℝ E
this : parallelepiped ⇑b \ fundamentalDomain b ⊆ ⋃ i, ↑(AffineSubspace.mk' (b i) (span ℝ (⇑b '' (Set.univ \ {i}))))
i : ι
⊢ AffineSubspace.mk' (b i) (span ℝ (⇑b '' (Set.univ \ {i}))) ≠ ⊤

tactic: refine (ne_of_mem_of_not_mem' (AffineSubspace.mem_top _ _ 0)
  (AffineSubspace.mem_mk'_iff_vsub_mem.not.mpr ?_)).symm
state_before: E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this✝ : FiniteDimensional ℝ E
this : parallelepiped ⇑b \ fundamentalDomain b ⊆ ⋃ i, ↑(AffineSubspace.mk' (b i) (span ℝ (⇑b '' (Set.univ \ {i}))))
i : ι
⊢ AffineSubspace.mk' (b i) (span ℝ (⇑b '' (Set.univ \ {i}))) ≠ ⊤
state_after: E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this✝ : FiniteDimensional ℝ E
this : parallelepiped ⇑b \ fundamentalDomain b ⊆ ⋃ i, ↑(AffineSubspace.mk' (b i) (span ℝ (⇑b '' (Set.univ \ {i}))))
i : ι
⊢ 0 -ᵥ b i ∉ span ℝ (⇑b '' (Set.univ \ {i}))

tactic: simp_rw [vsub_eq_sub, zero_sub, neg_mem_iff]
state_before: E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this✝ : FiniteDimensional ℝ E
this : parallelepiped ⇑b \ fundamentalDomain b ⊆ ⋃ i, ↑(AffineSubspace.mk' (b i) (span ℝ (⇑b '' (Set.univ \ {i}))))
i : ι
⊢ 0 -ᵥ b i ∉ span ℝ (⇑b '' (Set.univ \ {i}))
state_after: E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this✝ : FiniteDimensional ℝ E
this : parallelepiped ⇑b \ fundamentalDomain b ⊆ ⋃ i, ↑(AffineSubspace.mk' (b i) (span ℝ (⇑b '' (Set.univ \ {i}))))
i : ι
⊢ b i ∉ span ℝ (⇑b '' (Set.univ \ {i}))

tactic: exact linearIndependent_iff_not_mem_span.mp b.linearIndependent i
state_before: E : Type u_1
ι : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
b : Basis ι ℝ E
inst✝³ : Fintype ι
inst✝² : MeasurableSpace E
μ : Measure E
inst✝¹ : BorelSpace E
inst✝ : μ.IsAddHaarMeasure
this✝ : FiniteDimensional ℝ E
this : parallelepiped ⇑b \ fundamentalDomain b ⊆ ⋃ i, ↑(AffineSubspace.mk' (b i) (span ℝ (⇑b '' (Set.univ \ {i}))))
i : ι
⊢ b i ∉ span ℝ (⇑b '' (Set.univ \ {i}))
state_after: no goals