theorem
proved
tactic proof
phi10_fibonacci
show as:
view Lean formalization →
formal statement (Lean)
29theorem phi10_fibonacci : phi ^ 10 = 55 * phi + 34 := by
proof body
Tactic-mode proof.
30 have h2 := phi_sq_eq
31 have h3 : phi ^ 3 = 2 * phi + 1 := by nlinarith
32 have h4 : phi ^ 4 = 3 * phi + 2 := by nlinarith
33 have h5 : phi ^ 5 = 5 * phi + 3 := by nlinarith
34 have h10 : phi ^ 10 = phi ^ 5 * phi ^ 5 := by ring
35 rw [h10]; nlinarith
36
37/-- φ^10 > 100. -/