∀ (F : Type u_1) (E : Type u_2) [inst : Field F] [inst_1 : Field E] [inst_2 : Algebra F E] (L : IntermediateField F E)
  (motive : Algebra.IsSeparable F ↥L ∧ IsPurelyInseparable (↥L) E → Prop)
  (x : Algebra.IsSeparable F ↥L ∧ IsPurelyInseparable (↥L) E),
  (∀ (left : Algebra.IsSeparable F ↥L) (right : IsPurelyInseparable (↥L) E), motive ⋯) → motive x