lean_workbook_plus_68225

Disproved

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

Prove or disprove $a^4+b^4+c^4+4abc>1$ given $a^2+b^2+c^2=1$ where $a, b, c$ are positive reals.

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_68225 : ∀ a b c : ℝ, a^2+b^2+c^2=1 → a^4+b^4+c^4+4*a*b*c>1   :=  by sorry

Source