A fixed-sum quadratic reciprocal upper bound
ProvedWorkbookSource.base_368lean-workbooksource-checked
Prove that given and .
Source: InternLM Lean-Workbook, record lean_workbook_368 (Apache-2.0). Complete source proposition preserved; proof developed independently.
Preamble
import Mathlib open Real Nat
Formal statement
theorem WorkbookSource.base_368 (a b c : ℝ) (ha : 0 < a) (hb : 0 < b) (hc : 0 < c) (hab : a + b + c = 3) : (a^2 / (a + 2) + b^2 / (b + 2) + c^2 / (c + 2)) ≤ 3 / (a * b + b * c + a * c) := by sorry
Source