fpvandoorn/carleson
Source indexedlemma · leanprover/lean4:v4.32.0
biSup_Θ'_eq_biSup_enumΘ'
Carleson.MetricCarleson.Main · Carleson/MetricCarleson/Main.lean:83 to 96
Mathematical statement
Exact Lean statement
lemma biSup_Θ'_eq_biSup_enumΘ' {x : X} :
⨆ θ ∈ Θ' X, g θ x = ⨆ n, ⨆ i ∈ Finset.range (n + 1), g (enumΘ' nΘ' i) xComplete declaration
Lean source
Full Lean sourceLean 4
lemma biSup_Θ'_eq_biSup_enumΘ' {x : X} : ⨆ θ ∈ Θ' X, g θ x = ⨆ n, ⨆ i ∈ Finset.range (n + 1), g (enumΘ' nΘ' i) x := by apply le_antisymm · refine iSup₂_le fun θ mθ ↦ ?_ obtain ⟨n, hn⟩ := surjective_enumΘ' nΘ' ⟨θ, mθ⟩ have eg : g θ x = g (enumΘ' nΘ' n).1 x := by simp [hn] rw [eg] calc _ ≤ ⨆ i ∈ Finset.range (n + 1), g (enumΘ' nΘ' i) x := by have : n ∈ Finset.range (n + 1) := by rw [Finset.mem_range]; lia convert! le_iSup₂ _ this; rfl _ ≤ _ := le_iSup_iff.mpr fun _ a ↦ a n · refine iSup_le fun n ↦ iSup₂_le fun i mi ↦ ?_ obtain ⟨θ, mθ⟩ := enumΘ' nΘ' i; apply le_iSup₂ _ mθ