lean_workbook_plus_50219

Proved

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

If $|a-b|<\epsilon\,\forall\,\epsilon>0$ , then prove that $a=b$ .

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_50219  (a b : ℝ)
  (h : ∀ ε > 0, |a - b| < ε) :
  a = b   :=  by sorry

Source