Definition copy_trans (c : Config) (s1 s2 : Site) :=
  mkconfig (S (time c)) (dt c) (Inc_send_table (st c) s1) 
    (rt c) (Post_message copy (bm c) s1 s2).

Lemma copy_trans_st : forall s0 : Site, st (copy_trans c0 s1 s2) s0 = (if eq_site_dec s0 s1 then (st c0 s0 + 1)%Z else st c0 s0).