lean_workbook_plus_11972

Proved

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

Let $a,b$ be positive real numbers. Prove that $a^3b+ab^3+a+b \geqslant 2ab+a^2b+ab^2$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_11972 (a b : ℝ) (ha : 0 < a) (hb : 0 < b) : a^3 * b + a * b^3 + a + b ≥ 2 * a * b + a^2 * b + a * b^2   :=  by sorry

Source