lemma
proved
tactic proof
phi_eleventh_eq
show as:
view Lean formalization →
formal statement (Lean)
209lemma phi_eleventh_eq : phi^11 = 89 * phi + 55 := by
proof body
Tactic-mode proof.
210 calc phi^11 = phi * phi^10 := by ring
211 _ = phi * (55 * phi + 34) := by rw [phi_tenth_eq]
212 _ = 55 * phi^2 + 34 * phi := by ring
213 _ = 55 * (phi + 1) + 34 * phi := by rw [phi_sq_eq]
214 _ = 89 * phi + 55 := by ring
215
216/-! ### Canonical constants derived from φ -/
217
218/-- Canonical locked fine-structure constant: α_lock = (1 − 1/φ)/2. -/