fpvandoorn/carleson
Source indexedlemma · leanprover/lean4:v4.32.0
MeasureTheory.AESublinearOn.biSup2
Carleson.ToMathlib.RealInterpolation.Main · Carleson/ToMathlib/RealInterpolation/Main.lean:284 to 321
Mathematical statement
Exact Lean statement
lemma biSup2 {ι : Type*} {𝓑 : Set ι} (h𝓑 : 𝓑.Countable) {T : ι → (α → ε₁) → α' → ℝ≥0∞}
{P : (α → ε₁) → Prop} {Q : (α → ε₁) → Prop}
(hPT : ∀ (u : α → ε₁), P u → ∀ᵐ x ∂ν, ⨆ i ∈ 𝓑, T i u x ≠ ∞)
(hQT : ∀ (u : α → ε₁), Q u → ∀ᵐ x ∂ν, ⨆ i ∈ 𝓑, T i u x ≠ ∞)
(P0 : P 0)
(Q0 : Q 0)
(haP : ∀ {f g : α → ε₁}, P f → P g → P (f + g))
(haQ : ∀ {f g : α → ε₁}, Q f → Q g → Q (f + g))
(hsP : ∀ {f : α → ε₁} {c : ℝ≥0}, P f → P (c • f))
(hsQ : ∀ {f : α → ε₁} {c : ℝ≥0}, Q f → Q (c • f))
{A : ℝ≥0} -- todo, here and elsewhere: probably better to have {A : ℝ≥0∞} (hA : A ≠ ⊤)
(hAP : ∀ i ∈ 𝓑,
AESublinearOn (T i) (fun g ↦ g ∈ {f | P f} + {f | Q f}) A ν) :
AESublinearOn (fun u x ↦ ⨆ i ∈ 𝓑, T i u x) (fun f ↦ P f ∨ Q f) A νComplete declaration
Lean source
Full Lean sourceLean 4
lemma biSup2 {ι : Type*} {𝓑 : Set ι} (h𝓑 : 𝓑.Countable) {T : ι → (α → ε₁) → α' → ℝ≥0∞} {P : (α → ε₁) → Prop} {Q : (α → ε₁) → Prop} (hPT : ∀ (u : α → ε₁), P u → ∀ᵐ x ∂ν, ⨆ i ∈ 𝓑, T i u x ≠ ∞) (hQT : ∀ (u : α → ε₁), Q u → ∀ᵐ x ∂ν, ⨆ i ∈ 𝓑, T i u x ≠ ∞) (P0 : P 0) (Q0 : Q 0) (haP : ∀ {f g : α → ε₁}, P f → P g → P (f + g)) (haQ : ∀ {f g : α → ε₁}, Q f → Q g → Q (f + g)) (hsP : ∀ {f : α → ε₁} {c : ℝ≥0}, P f → P (c • f)) (hsQ : ∀ {f : α → ε₁} {c : ℝ≥0}, Q f → Q (c • f)) {A : ℝ≥0} -- todo, here and elsewhere: probably better to have {A : ℝ≥0∞} (hA : A ≠ ⊤) (hAP : ∀ i ∈ 𝓑, AESublinearOn (T i) (fun g ↦ g ∈ {f | P f} + {f | Q f}) A ν) : AESublinearOn (fun u x ↦ ⨆ i ∈ 𝓑, T i u x) (fun f ↦ P f ∨ Q f) A ν := by set R := fun g ↦ g ∈ {f | P f} + {f | Q f} have hPR : ∀ {f}, P f → R f := fun hu ↦ ⟨_, hu, 0, Q0, by simp⟩ have hQR : ∀ {f}, Q f → R f := fun hu ↦ ⟨0, P0, _, hu, by simp⟩ apply AESublinearOn.antitone (P' := R) (fun hu ↦ hu.elim hPR hQR) refine AESublinearOn.biSup (P := R) h𝓑 ?_ ?_ ?_ hAP · rintro _ ⟨f, hf, g, hg, rfl⟩ filter_upwards [hPT f hf, hQT g hg, AESubadditiveOn.forall_le h𝓑 (fun i hi ↦ hAP i hi |>.1) (hPR hf) (hQR hg)] with x hfx hgx hTx simp_rw [← lt_top_iff_ne_top] at hfx hgx ⊢ simp_rw [enorm_eq_self] at hTx calc _ ≤ ⨆ i ∈ 𝓑, A * (T i f x + T i g x) := by gcongr; exact hTx _ ‹_› _ ≤ A * ((⨆ i ∈ 𝓑, T i f x) + (⨆ i ∈ 𝓑, T i g x)) := by simp_rw [← ENNReal.mul_iSup] gcongr -- todo: make lemma simp_rw [iSup_le_iff] intro i hi gcongr <;> apply le_biSup _ hi _ < ⊤ := mul_lt_top coe_lt_top <| add_lt_top.mpr ⟨hfx, hgx⟩ · rintro _ _ ⟨f₁, hf₁, g₁, hg₁, rfl⟩ ⟨f₂, hf₂, g₂, hg₂, rfl⟩ exact ⟨f₁ + f₂, haP hf₁ hf₂, g₁ + g₂, haQ hg₁ hg₂, by dsimp only; abel_nf⟩ · rintro _ c ⟨f, hf, g, hg, rfl⟩ exact ⟨c • f, hsP hf, c • g, hsQ hg, by module⟩