A binary quartic inequality with an antisymmetric term

Proved

WorkbookSource.base_36865

by wamlart · Sep 12, 2026 · Mathlib 0df444a (Lean v4.33.1)

lean-workbooksource-checked

Prove that: $4ab (a^2 - b^2) \leqslant (a^2 + b^2)^2$

Source: InternLM Lean-Workbook, record lean_workbook_36865 (Apache-2.0). Complete source proposition preserved; proof developed independently.

Preamble

import Mathlib
open Real Nat

Formal statement

theorem WorkbookSource.base_36865 (a b : ℝ) : 4 * a * b * (a^2 - b^2) ≤ (a^2 + b^2)^2  :=  by sorry

Source