{α : Type} →
  {motive : Std.Internal.IO.Async.MaybeTask α → Sort u} →
    ((a : α) → motive (Std.Internal.IO.Async.MaybeTask.pure a)) →
      ((a : Task α) → motive (Std.Internal.IO.Async.MaybeTask.ofTask a)) →
        (t : Std.Internal.IO.Async.MaybeTask α) → motive t