{motive : Lean.Grind.CommRing.Expr → Sort u} →
  (t : Lean.Grind.CommRing.Expr) →
    ((k : ℤ) → motive (Lean.Grind.CommRing.Expr.num k)) →
      ((i : Lean.Grind.CommRing.Var) → motive (Lean.Grind.CommRing.Expr.var i)) →
        (Nat.hasNotBit 9 t.ctorIdx → motive t) → motive t