lean_workbook_plus_24316

Proved

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

Let $a,b,c$ be positive real numbers. Prove that ${\left(1+ \frac{2a}{b+c}\right)\left(1+ \frac{2b}{c+a}\right)\left(1+ \frac{2c}{a+b} \right)}\ge 2$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_24316 (a b c : ℝ) (ha : a > 0) (hb : b > 0) (hc : c > 0) : (1 + 2 * a / (b + c)) * (1 + 2 * b / (c + a)) * (1 + 2 * c / (a + b)) ≥ 2   :=  by sorry

Source

https://huggingface.co/datasets/internlm/Lean-Workbook

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