Notation coh := LockCoh.Definition server_send_safe (this n : nid)
           (d : dstatelet) (msg : seq nat) :=
  HServ this n /\
  exists (C : coh d), prec (getSt_server C) n msg.

(* Specifications: *)
Lemma server_send_safe_coh this to d m : server_send_safe this to d m -> coh d.
Lemma server_step_coh : s_step_coh_t coh the_tag server_step.
Lemma server_step_def this to d msg : server_send_safe this to d msg <-> exists b pf, @server_step this to d msg pf = Some b.