A sixth-degree upper bound at fixed sum three
ProvedWorkbookSource.base_31427lean-workbooksource-checked
But easy to prove that is true for all non-negative and such that
Source: InternLM Lean-Workbook, record lean_workbook_31427 (Apache-2.0). Complete source proposition preserved; proof developed independently.
Preamble
import Mathlib open Real Nat
Formal statement
theorem WorkbookSource.base_31427 (u v w : ℝ) (hu : 0 ≤ u) (hv : 0 ≤ v) (hw : 0 ≤ w) (h : u + v + w = 3) : 16 ≥ 7 * u^2 * v^2 * w^2 + 3 * (u^2 * v^2 + u^2 * w^2 + v^2 * w^2) := by sorry
Source