lean_workbook_plus_43561

Proved

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

Let $\frac{a}{b}=x$ and $\frac{b}{c}=y$ so $x$ and $y$ are $\geq1$ . Inequality equivalents to $(y^3-y^2)x^3+x^2-(y^2+1)x+y \geq0$ .

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_43561 (x y : ℝ) (hx : 1 ≤ x) (hy : 1 ≤ y) : (y^3 - y^2) * x^3 + x^2 - (y^2 + 1) * x + y ≥ 0   :=  by sorry

Source