fpvandoorn/carleson
Source indexedlemma · leanprover/lean4:v4.32.0
TileStructure.Forest.volume_le_of_kissing
Carleson.ForestOperator.L2Estimate · Carleson/ForestOperator/L2Estimate.lean:417 to 437
Mathematical statement
Exact Lean statement
lemma volume_le_of_kissing (h : J ∈ kissing I) :
volume (ball (c I) (33 * D ^ s I)) ≤ 2 ^ (9 * a) * volume (ball (c J) (D ^ s J / 4))Complete declaration
Lean source
Full Lean sourceLean 4
lemma volume_le_of_kissing (h : J ∈ kissing I) : volume (ball (c I) (33 * D ^ s I)) ≤ 2 ^ (9 * a) * volume (ball (c J) (D ^ s J / 4)) := by simp_rw [kissing, Finset.mem_filter_univ] at h obtain ⟨x, xI, xJ⟩ := not_disjoint_iff.mp h.2 have : ball (c I) (33 * D ^ s I) ⊆ ball (c J) (128 * D ^ s J) := by apply ball_subset_ball' calc _ ≤ 33 * D ^ s I + dist (c I) x + dist x (c J) := by rw [add_assoc]; exact add_le_add_right (dist_triangle ..) _ _ ≤ 33 * D ^ s I + 16 * D ^ s I + 16 * D ^ s J := by gcongr · exact (mem_ball'.mp xI).le · exact (mem_ball.mp xJ).le _ ≤ _ := by rw [h.1, ← distrib_three_right] gcongr; norm_num have double := @measure_ball_two_le_same_iterate X _ _ _ volume _ (c J) (D ^ s J / 4) 9 have A9 : (defaultA a : ℝ≥0) ^ 9 = (2 : ℝ≥0∞) ^ (9 * a) := by simp only [defaultA]; norm_cast; ring rw [show (2 : ℝ) ^ 9 * (D ^ s J / 4) = 128 * D ^ s J by ring, A9] at double exact (measure_mono this).trans double