∀ {α : Type u_1} {a : Lists α} (motive : (x : Lists α) → a ∈ x → Prop) (x : Lists α) (x_1 : a ∈ x),
  (∀ (x : a ∈ ⟨true, Lists'.nil⟩), motive ⟨true, Lists'.nil⟩ x) →
    (∀ (b : Bool) (a_1 : Lists' α b) (a_2 : Lists' α true) (x : a ∈ ⟨true, a_1.cons' a_2⟩),
        motive ⟨true, a_1.cons' a_2⟩ x) →
      motive x x_1