Theorem no_entries_past_current_term_nw_not_append_entries : forall net ps' p' st', no_entries_past_current_term_nw net -> (forall p, In p ps' -> In p (nwPackets net) \/ p = p') -> ~ is_append_entries (pBody p') -> no_entries_past_current_term_nw (mkNetwork ps' st').