lean_workbook_plus_79601

import Mathlib.Analysis.Complex.Basic

theorem lean_workbook_plus_79601 (a b c : ℝ) (ha : 0 < a) (hb : 0 < b) (hc : 0 < c) : (a / (a * b + a + 1) + b / (b * c + b + 1) + c / (c * a + c + 1)) ≤ 1   :=  by sorry