lean_workbook_plus_17848

Proved

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

Find the function $f(x)$ that satisfies the equation $f(x+1)f(x) = x$ for all $x$ in the domain $\mathbb{R} \setminus \{0\}$ .

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_17848 (x : ℝ) (hx : x ≠ 0) : ∃ f : ℝ → ℝ, f (x + 1) * f x = x   :=  by sorry

Source