lean_workbook_plus_40945

Proved

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

Prove that if $\left | a-b \right |<\frac{\left | b \right |}2$ , then $\left | a \right |>\frac{\left | b \right |}{2}$ . \na,b are real numbers

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_40945 (a b : ℝ) (h : abs (a - b) < abs b / 2) : abs a > abs b / 2   :=  by sorry

Source