lean_workbook_plus_47800

Proved

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

Let $a,b >0$ and $\dfrac{1}{1+a}+\dfrac{2}{1+b} \le 1.$ Prove that \n

a b^2\geq 8

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_47800 (a b : ℝ) (ha : 0 < a) (hb : 0 < b) (hab : 1 / (1 + a) + 2 / (1 + b) ≤ 1) : a * b^2 ≥ 8   :=  by sorry

Source