Section INVARIANT1.

Lemma invariant1_inductive :
forall (c : Config) (t : class_trans c),
legal c ->
sigma_send_table (st c) =
(sigma_receive_table (rt c) + sigma_weight (bm c))%Z ->
sigma_send_table (st (transition c t)) =
(sigma_receive_table (rt (transition c t)) +
sigma_weight (bm (transition c t)))%Z.