lean_workbook_plus_75855

Disproved

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

Prove that $x^{4}(y+z)+y^{4}(z+x)+z^{4}(y+x)\leq\frac{1}{12}\left(x+y+z\right)^{5}$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_75855 : ∀ x y z : ℝ, x^4 * y + x^4 * z + y^4 * z + y^4 * x + z^4 * y + z^4 * x ≤ (1/12) * (x + y + z)^5   :=  by sorry

Source