Definition server_recv_trans := ReceiveTrans sr_step_coh.Definition can_send (s : cstate) to msg :=
  has (entry_finder to msg) s.

(* Specifications: *)
Lemma ss_safe_coh this to d m : ss_safe this to d m -> coh d.
Lemma ss_step_coh : s_step_coh_t coh resp ss_step.
Lemma ss_safe_def this to d msg : ss_safe this to d msg <-> exists b pf, @ss_step this to d msg pf = Some b.