lean_workbook_plus_74455

Disproved

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

$\frac{4}{\frac{a}{1-a}+\frac{b}{1-b}+\frac{c}{1-c}+\frac{d}{1-d}} \geq 1$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_74455 : ∀ a b c d : ℝ, (4 / (a / (1 - a) + b / (1 - b) + c / (1 - c) + d / (1 - d))) ≥ 1   :=  by sorry

Source