Section NetworkSemantics.
Variable w : world.
Variable this: nid.
Notation getl := (getLocal).
Notation gets := (getStatelet).
Notation getp := (@getProtocol w).
(* Getters for transitions *)
Definition get_coh l := @coh (getp l).
Definition get_st l := @snd_trans (getp l).
Definition get_rt l := @rcv_trans (getp l).

(* Stepping preserves the protocol structure *)
Lemma step_preserves_labels s1 s2 :
network_step s1 s2 -> dom s1 =i dom s2.