lean_workbook_plus_67254

Proved

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

Let then $u=\frac{1+\sqrt 5}2$ such that $u^2=u+1$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_67254 (u : ℝ) (hu : u = (1 + Real.sqrt 5) / 2) : u^2 = u + 1   :=  by sorry

Source