lean_workbook_plus_7114

Proved

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

1 : $\boxed{f(x)=x}$ $\forall x$ , which indeed is a solution

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_7114 : ∃ f : ℝ → ℝ, ∀ x, f x = x   :=  by sorry

Source