∀ {R : Type u_1} {S : Type u_2} [inst : CommRing R] [inst_1 : CommRing S] [inst_2 : Algebra R S] {a : S}
  (motive : IsAlgebraic R a → Prop) (x : IsAlgebraic R a),
  (∀ (f : Polynomial R) (hf₁ : f ≠ 0) (hf₂ : (Polynomial.aeval a) f = 0), motive ⋯) → motive x