(motive : Option (Aesop.OrderedHashSet Aesop.Substitution) → Sort u_1) →
  (x : Option (Aesop.OrderedHashSet Aesop.Substitution)) →
    (Unit → motive none) → ((insts : Aesop.OrderedHashSet Aesop.Substitution) → motive (some insts)) → motive x