∀ (F : Type u_1) [inst : Field F] {E : Type u_2} [inst_1 : Field E] [inst_2 : Algebra F E] {α : E} {K : Type u}
  [inst_3 : Field K] [inst_4 : Algebra F K],
  IsIntegral F α →
    IsSeparable F α →
      (Polynomial.map (algebraMap F K) (minpoly F α)).Splits → Nat.card (↥F⟮α⟯ →ₐ[F] K) = (minpoly F α).natDegree