∀ {n : Type u_1} {𝕜 : Type u_2} [inst : RCLike 𝕜] [inst_1 : Fintype n] [inst_2 : DecidableEq n] {A : Matrix n n 𝕜}
  (hA : A.IsHermitian) (f : ℝ → ℝ), (cfc f A).charpoly = ∏ i, (Polynomial.X - Polynomial.C ↑(f (hA.eigenvalues i)))