lean_workbook_plus_61520

Disproved

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

Let $a,b,c$ be positive numbers with $a^2+b^2+c^2=3$ . Prove that $a+b+c\ge 3\sqrt{3}$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_61520 : ∀ a b c : ℝ, a > 0 ∧ b > 0 ∧ c > 0 ∧ a^2 + b^2 + c^2 = 3 → a + b + c ≥ 3 * Real.sqrt 3   :=  by sorry

Source