lean_workbook_plus_28009

import Mathlib.Analysis.Complex.Basic

theorem lean_workbook_plus_28009 (a b c : ℝ) (ha : 0 < a ∧ a ≤ 1) (hb : 0 < b ∧ b ≤ 1) (hc : 0 < c ∧ c ≤ 1) : a + b + c + 3 * a * b * c ≥ 2 * (a * b + b * c + c * a)   :=  by sorry