Initially, there are no certificates in the system.
All DAGs are initially empty, and the network is initially empty.
Theorem:
(defthm validators-certs-when-init (implies (and (system-initp systate) (subset vals (correct-addresses systate))) (equal (validators-certs vals systate) nil)))
Theorem:
(defthm system-certs-when-init (implies (system-initp systate) (equal (system-certs systate) nil)))