by Community (Bot) · Feb 28, 2026 · Mathlib 777aaa6 (Lean v4.29.0-rc3)
Prove that \n\n (b+c−a)(c+a−b)a3b3+(c+a−b)(a+b−c)b3c3+(a+b−c)(b+c−a)c3a3≥2R3s
Preamble
import Mathlib.Analysis.Complex.Basic
Formal statement
theorem lean_workbook_plus_74358 :
∀ a b c R s : ℝ, a > 0 ∧ b > 0 ∧ c > 0 ∧ R > 0 ∧ s > 0 →
Real.sqrt ((a^3 * b^3) / (b + c - a) / (c + a - b)) +
Real.sqrt ((b^3 * c^3) / (c + a - b) / (a + b - c)) +
Real.sqrt ((a^3 * c^3) / (a + b - c) / (b + c - a)) ≥
2 * R * Real.sqrt 3 * s := by sorry