{motive : (a : Tactic.ComputeAsymptotics.Basis) → Tactic.ComputeAsymptotics.BasisExtension a → Sort u} →
  {a : Tactic.ComputeAsymptotics.Basis} →
    (t : Tactic.ComputeAsymptotics.BasisExtension a) →
      ((a : Tactic.ComputeAsymptotics.Basis) →
          (t : Tactic.ComputeAsymptotics.BasisExtension a) →
            Tactic.ComputeAsymptotics.BasisExtension.below t → motive a t) →
        motive a t ×' Tactic.ComputeAsymptotics.BasisExtension.below t