Instance log_base_params : BaseParams := @log_base_params orig_base_params.Instance log_multi_params : DiskOpMultiParams log_base_params := log_multi_params snapshot_interval.Instance log_failure_params : DiskOpFailureParams log_multi_params := log_failure_params snapshot_interval.Definition disk_correct dsk h st  :=
    exists s (entries : list entry) (snap : data),
      dsk Count = Some (serialize (length entries)) /\
      dsk Log = Some s /\
      IOStreamWriter.unwrap s = IOStreamWriter.unwrap (list_serialize_rec entry _ entries) /\
      dsk Snapshot = Some (serialize snap) /\
      log_num_entries st = length entries /\
      (apply_log h snap entries = log_data st).

Lemma disk_correct_invariant : forall net failed tr, @step_failure_disk_ops_star _ _ log_failure_params step_failure_disk_ops_init (failed, net) tr -> forall h, disk_correct (nwdoDisk net h) h (nwdoState net h).