fpvandoorn/carleson
Source indexedlemma · leanprover/lean4:v4.32.0
TileStructure.Forest.ψ_le_max
Carleson.ForestOperator.LargeSeparation · Carleson/ForestOperator/LargeSeparation.lean:482 to 492
Mathematical statement
Exact Lean statement
lemma ψ_le_max [ProofData a q K σ₁ σ₂ F G] {x : ℝ} : ψ x ≤ max 0 ((2 - 4 * x) ^ (a : ℝ)⁻¹)Complete declaration
Lean source
Full Lean sourceLean 4
lemma ψ_le_max [ProofData a q K σ₁ σ₂ F G] {x : ℝ} : ψ x ≤ max 0 ((2 - 4 * x) ^ (a : ℝ)⁻¹) := by by_cases! h₁ : x ≤ 1 / 4 · exact (ψ_le_one ..).trans ((Real.one_le_rpow (by linarith) (by simp)).trans (le_max_right ..)) by_cases! h₂ : 1 / 2 ≤ x · rw [ψ_formula₄ h₂]; exact le_max_left .. rw [ψ_formula₃ (one_lt_realD X) ⟨h₁.le, h₂.le⟩] refine le_trans ?_ (le_max_right ..) set y := 2 - 4 * x; apply Real.self_le_rpow_of_le_one · unfold y; linarith · unfold y; linarith · exact Nat.cast_inv_le_one a