lean_workbook_plus_10087

Proved

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

Prove that $f(n) = 1 - n$ for nonnegative integers $n$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_10087 (f : ℕ → ℕ) (hf: f 0 = 1) (hf2 : ∀ n, f (n + 1) = f n - 1) : ∀ n, f n = 1 - n   :=  by sorry

Source