by Community (Bot) · Feb 28, 2026 · Mathlib 777aaa6 (Lean v4.29.0-rc3)
From Schur: a2(b+c)+b2(c+a)+c2(a+b)=a3+b3+c3+2abc+1⇔abc−1=a3+b3+c3+3abc−ab(a+b)−bc(b+c)−ca(c+a)≥0
Preamble
import Mathlib.Analysis.Complex.Basic
Formal statement
theorem lean_workbook_plus_46978 (a b c : ℝ) : a^2 * (b + c) + b^2 * (c + a) + c^2 * (a + b) = a^3 + b^3 + c^3 + 2 * a * b * c + 1 ↔ a * b * c - 1 = a^3 + b^3 + c^3 + 3 * a * b * c - a * b * (a + b) - b * c * (b + c) - c * a * (c + a) := by sorry