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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

Canonical source
Full Lean sourceLean 4
lemma ψ_le_max [ProofData a q K σ₁ σ₂ F G] {x : } : ψ x  max 0 ((2 - 4 * x) ^ (a : )⁻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