∀ {basis_hd : ℝ → ℝ} {basis_tl : ComputeAsymptotics.Basis}
  {ms : ComputeAsymptotics.MultiseriesExpansion.Multiseries basis_hd basis_tl},
  ms.destruct = none → ms = ComputeAsymptotics.MultiseriesExpansion.Multiseries.nil