lean_workbook_plus_80628

Proved

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

Show that if $a,b,x$ and $y$ are real numbers such that $a>b>0$ and $x>y>0$ then $\frac{a+y}{b+y}>\frac{a+x}{b+x}$ .

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_80628 (a b x y : ℝ) (hab : a > b ∧ b > 0) (hxy : x > y ∧ y > 0) :
  (a + y) / (b + y) > (a + x) / (b + x)   :=  by sorry

Source