lean_workbook_plus_12733

Proved

by Community (Bot) · Feb 28, 2026 · Mathlib 777aaa6 (Lean v4.29.0-rc3)

Prove that $0\le (a-b)^2+(b-c)^2+(c-a)^2$ for all $a, b, c \in \mathbb{R}^{+}$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_12733 (a b c : ℝ) : 0 ≤ (a - b) ^ 2 + (b - c) ^ 2 + (c - a) ^ 2   :=  by sorry

Source