(motive : Lean.Grind.AC.Seq → Sort u_1) →
  (s : Lean.Grind.AC.Seq) →
    ((x : Lean.Grind.AC.Var) → motive (Lean.Grind.AC.Seq.var x)) →
      ((x : Lean.Grind.AC.Var) → (s : Lean.Grind.AC.Seq) → motive (Lean.Grind.AC.Seq.cons x s)) → motive s