Program Definition age1_juicy_mem (j: juicy_mem): option juicy_mem :=
      match age1 (m_phi j) with
        | Some phi' => Some (mkJuicyMem (m_dry j) phi' _ _ _ _)
        | None => None
      end.

Lemma juicy_mem_ageable_facts: ageable_facts juicy_mem (fun j => level (m_phi j)) age1_juicy_mem.