lean_workbook_plus_69111

Disproved

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

I think this is better:\n $\frac{1}{a(b+c)}+\frac{1}{b(a+c)}+\frac{1}{c(a+b)}\leq\frac{18}{23}$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_69111 : ∀ a b c : ℝ, (1 / (a * (b + c)) + 1 / (b * (a + c)) + 1 / (c * (a + b))) ≤ (18:ℝ) / 23   :=  by sorry

Source