lean_workbook_plus_79898
Provedprove that \n\na,b,c - triangle side lengths.
Preamble
import Mathlib.Analysis.Complex.Basic
Formal statement
theorem lean_workbook_plus_79898 (a b c : ℝ) (hx: a > 0 ∧ b > 0 ∧ c > 0) (hab : a + b > c) (hbc : b + c > a) (hca : a + c > b) : a^2 * (b + c - a) + b^2 * (a + c - b) + c^2 * (a + b - c) ≤ 3 * a * b * c := by sorry
Source