∀ {α : Type u} {σ : Type v} {M : εNFA α σ} {S : Set σ} {motive : (a : σ) → M.εClosure S a → Prop} (s t : σ)
  (a : t ∈ M.step s none) (a_1 : M.εClosure S s), εNFA.εClosure.below a_1 → motive s a_1 → εNFA.εClosure.below ⋯