{motive_2 : Lean.IR.FnBody → Sort u} →
  (t : Lean.IR.FnBody) →
    ((tid : Lean.Name) →
        (x : Lean.IR.VarId) →
          (xType : Lean.IR.IRType) → (cs : Array Lean.IR.Alt) → motive_2 (Lean.IR.FnBody.case tid x xType cs)) →
      (Nat.hasNotBit 512 t.ctorIdx → motive_2 t) → motive_2 t