theorem
proved
tactic proof
FApply_square
show as:
view Lean formalization →
formal statement (Lean)
214theorem FApply_square {n : ℕ}
215 (lam : ℝ) (hInv : Fin n → Fin n → ℝ) (β : Vec n)
216 (hμ : mu lam hInv β ≠ 0) (v : Vec n) :
217 FApply lam hInv β (FApply lam hInv β v) = v := by
proof body
Tactic-mode proof.
218 ext i
219 have hPFi : PApply lam hInv β (FApply lam hInv β v) i = PApply lam hInv β v i := by
220 simpa using congrFun (PApply_FApply lam hInv β hμ v) i
221 calc
222 FApply lam hInv β (FApply lam hInv β v) i
223 = (2 • PApply lam hInv β (FApply lam hInv β v) - FApply lam hInv β v) i := by
224 simp [FApply]
225 _ = (2 • PApply lam hInv β v - FApply lam hInv β v) i := by
226 simp [hPFi]
227 _ = v i := by
228 simp [FApply]
229