lean_workbook_plus_5508

Proved

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

Let $a,b>0$ and $ab=1.$ Prove that \n

\frac{1}{a}+\frac{1}{b}+\frac{4}{a+b}\ge 4

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_5508 (a b : ℝ) (ha : 0 < a) (hb : 0 < b) (hab : a * b = 1) : 1 / a + 1 / b + 4 / (a + b) ≥ 4   :=  by sorry

Source