Theorem no_entries_past_current_term_nw_only_new_packets_matter : forall net ps' l st', no_entries_past_current_term_nw net -> (forall p, In p ps' -> In p (nwPackets net) \/ In p l) -> no_entries_past_current_term_nw (mkNetwork l st') -> no_entries_past_current_term_nw (mkNetwork ps' st').