theorem
proved
tactic proof
abs_deviation_small
show as:
view Lean formalization →
formal statement (Lean)
76theorem abs_deviation_small {r : ℝ} (hr : 0 < r) {δ : ℝ} (hδ : 0 ≤ δ)
77 (hδ_small : δ ≤ 1) (hJ : Jcost r ≤ δ) :
78 |r - 1| ≤ Real.sqrt (8 * δ) := by
proof body
Tactic-mode proof.
79 have hsq := edge_deviation_small hr hδ hδ_small hJ
80 have h8δ_nn : 0 ≤ 8 * δ := by nlinarith
81 rw [← Real.sqrt_sq (abs_nonneg (r - 1))]
82 apply Real.sqrt_le_sqrt
83 rw [sq_abs]
84 exact hsq
85
86/-! ## Part 2: Exact Case Recovery -/
87
88/-- **EXACT CASE RECOVERY**: When δ = 0, approximate holography recovers
89 exact holography (GCIC rigidity). -/