Proof using.
intros; destruct net, net'.
simpl in *.
subst.
auto.
Qed.
Definition sequence_sane (net : seq_num_network) :=
(forall p,
In p (nwPackets net) ->
tmNum (pBody p) < (tdNum ((nwState net) (pSrc p)))).

Lemma reachable_sane :
true_in_reachable step_dup step_async_init sequence_sane.