lean_workbook_plus_6592

Proved

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

If $f(\mathbb R)=\{0\}$ , we get solution $\boxed{\text{S1 : }f(x)=0\text{ }\forall x}$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_6592 (f : ℝ → ℝ): f '' Set.univ = {0} → ∀ x, f x = 0   :=  by sorry

Source